Okay, that's a tease.  It doesn't exist, not in this life or the next.

It's easy to realize why.  The perfect camera carrying system would be extremely lightweight, very small, roomy enough to carry all your present equipment and anything you buy in the future, hold all your stuff perfectly secure and safe from all the elements and possible theft, allow you instant and convenient access to everything, be able to be securely fastened on your person and quickly removed when you don't want it there, and cost almost nothing.

With so many contradictory requirements it's little wonder that most of us will spend our photography lives buying different bags, backpacks, cases, beltpacks and holders of all shapes and sizes in search of the holy grail of portability.

The D30 (or any EOS body) along with some large Canon lenses complicate the search enormously.  When all you're trying to carry is a little Nikon 990, for example, you can find literally dozens of suitable cases.  I didn't even buy anything new -- I had several camcorder and P&S cases that fit just fine.

I have a system for my D30 (and pro lenses) that works for me, and I describe it below.  Whether it works for you depends upon how close your shooting requirements meet mine, but at least it will give you some ideas.

Carrying Case -- LowePro Nature Trekker AW

The case I use for transporting my D30 and various lenses is the LowePro Nature Trekker AW (the AW stands for "All Weather" and it basically means there is an attached nylon cover that can come out and protect the entire backpack against rain) backpack.

LowePro makes very nice products, and their backpack line is considered among the very finest for photographers all over the world.  They have a graduated series of backpacks that range from the very small (a body and a lens or two) to the enormous (all the camera equipment you'll ever own in your life).  As with most good camera cases the stuff is configurable by moving around various velcroed compartments.

The Nature Trekker fits my stuff really well, although when I bought my 100mm macro I suddenly became a little cramped.  I can fit all three of my pro lenses (17-35, 28-70 and 70-200 2.8 L), the teleconverters (1.4x and 2x), a 420EX flash and the aforementioned macro lens, all along with the D30 body complete with camera grip.

I can't fit much of anything else, however, which means the rest of my flash kit (the 550, the other 420 and the ST-E2) nor my 50mm lens.  I've reached the point where I'll probably have to go to the next size up (the Photo Trekker) to keep everything together.

Aside from that the Trekker is very nice indeed, holding everything snugly and securely, fitting in the overhead compartment of a plane, and quite comfortable in the backpack position.

Shooting Case -- Kinesis belt pack system

You will not be shooting out of a backpack, however.  The first time you take the pack off, put it on the ground, open it up and get out a lens (and then reverse the process) you'll quickly understand why such a system is only good for transporting, and not for actively shooting.

For shooting absolutely nothing on this planet beats the Kinesis belt system stuff.  It's pricey and worth every penny.  Well constructed and easily configurable to fit whatever shooting situation you'll have that day, I can attest to how well this system works.  I've worn it for ten hours at a stretch (and I'm an old, broken-down man).  No matter what your lens configurations, this will hold it for you.

It essentially consists of three parts: a belt with a loop system for attachments, a harness that fits to the belt to take the weight off your hips, and the various lens cases and camera bags that fit onto the belt.  You buy all the parts separately and put together what you need, although the Kinesis people are extremely helpful at sorting out just what will work for you.

I have the belt, the padded harness (you can get the unpadded one if you think you'll be wearing it with another backpack at the same time), three lens cases (for my three L lenses), an accessory bag (for holding TCs and/or flashes, batteries or anything else you could need) and a camera bag (which I almost never use).  I usually carry the D30 in my hand and change lenses as needed from my belt -- very easy to do as long as you follow the rule you need at least as many lens cases as you have lenses (even though one will always be empty, since it's on your camera.  However, you need a place to put one lens while you mount the other on the camera, a mistake I made early on that resulting in a lot of lens juggling).

About the only things I don't like about the Kinesis stuff is how difficult it is to get on and off when using the harness (for an old man like myself, a two person job which my wife is happy to oblige) and the fact the various attachments that fit to the belt are somewhat difficult to put on and off (I start off the day putting together my belt with what I need, changing as required).

Those are minor quibbles -- this is the system the pros use, and for good reason. 

Camera Bag -- LowePro Orion Belt Bag

If you don't change lenses but still need something to carry your D30 around in, you have a lot more choices.  For my backup D30 my wife carries we've settled on the LowePro Orion Belt Bag (we bought it separately but it's also available as part of a backpack/beltbag combo).

This bag does fit the D30 with the 28-135mm IS lens with hood in shooting position, which is probably the largest all-purpose lens most people will be using with the D30.  I don't have a battery grip on the backup D30, but my D30 with grip fits just fine in the case (although to fit the D30 with lens and hood in the case you can't put it in the "normal" position of lens facing away from you, but need to position it lengthwise).

Unlike my backpack and Kinesis belt system, I'm not convinced the Orion belt bag is the ultimate D30 belt solution.  I'd like to find something that would carry the camera, on the belt, with the lens pointing straight down.  I know there are bags out there that have this configuration, but I haven't found one yet (it's tough when you live in a small town without photo stores, since looking at stuff online doesn't really tell you how it will fit).

If someone finds/has something better, please write.