another thing that may annoy the "purists"... (because i can...)
the sensor and software in the "new" canon series cameras (eg 350D vs 300D, 20D vs 10D etc) has an amazing low light capability. even pics at iso 1600 in bad light are quite clear, amazingly free of noise, with high contrast and resolution.
so what? wellllll.....
don't despair if you cant afford an IS lens. just swing camera mode dial to "P" mode, run the iso up (100iso is "normal") and shoot away. if u up the iso from 100 to 800, you can reduce exposure time 8 fold (3 stops). ie an exposure of 1/15s becomes 1/120s, more than fast enough to hold by hand. you do trade off some resolution, but unless you are printing posters, you wont really know. compare this to film, where even porfessinal 800 speed film will produce grainy pics in low light, that is noticeable even at 6x4 print size.
just my tuppence worth...
oh, and just a bit more on the 75-300mm lens. quality = weight. the cheap lenses are light. good lenses weigh a ton. add that to an already beefy 350D, and you have a handful. ok for the occassional snap, but if you're waiting in baited breath for that bird to take off, your arms may give up before your patience. i have (amatuer) shot a few weddings using a 20D with battery pack, 550EX speedlite and 28-135mm IS USM lens. the package weighed close to 2kg. after 4 hrs i was getting a little tired of holding the darn thing up. the cheap lens artifacts are less of an issue in digital, as optics are better in the middle of the lens, and digital crops the image down 2/3 in size.
make it a thrippence