I've had a Conon 300D since June, and use it with the lenses that I had for my 12 year old (and still going strong) EOS 1000. The lenses are standard 105m zoom, 75-300m zoom and 100m(?)-500m Sigma zoom. The 500 zoom is sharp enough for me to see a fellow in a wheel chair who was 2500 metres away from where I took the photo. The 300D is a great camera but naturally enough I'm a bit envious that the 20D doesn't cost much more now than the 300D did last June.
Don't forget to factor in the scan disc cost. I bought a 1 gb disc but I think that 6 gb discs are available. Plaza Digital (upstairs in Plaza Arcade, Murray Street end) and Camera & Video in City Arcade (Murray Street level and end) are two shops worth visiting. Michael Hawkins.