Canon doesn't have a superzoom. I've tested two independents - the Sigma
18-200mm OS (on Sigma) and the Tamron VC 28-300mm (on both Canon full
frame and APS-C). Obviously the Tamron has no real wide-angle end on
APS-C but a very impressive tele reach. While the Tamron appears to be
optically very good, the stabilisation is quirky. The Sigma is just not
very good at all unless you turn the OS off.

You will note that both are stabilised. I would not use a superzoom with
an effective reach over 300mm in fullframe terms, and the associated
good macro/close up abilities, and the associated very limited maximum
aperture, without image stabilisation.

For your price I'd say a Sony Alpha 200 (not yet available, due next
week) with either a Sony 18-250mm zoom or the Tamron 18-250mm zoom. This
particular lens design is probably the best superzoom currently made (it
beats all the 18-200mm designs for sharpness and clean imaging).

Your price might just be possible with the Sony branded version - it's
the same lens at heart but the Sony has a faster focusing mechanism. The
alternative could be a Pentax K10D (price just dropped because of the
K20D arrival) with their similar, slightly wider aperture, 18-200mm, or
again the Tamron 18-250mm; or the Nikon D40X with the 18-200mm VR
stabilised Nikon lens (or Sigma alternative).

The only option which doesn't tick the right box is Canon, whose 1.6X
sensor factor immediately makes the 18mm end less wide-angle, and which
offers no in-body stabilisation, and doesn't have a Canon own brand
superzoom, or a stabilised superzoom - the Sigma is pretty much the only
choice and the combo of a Canon 400D plus Sigma won't give you the
optical quality or zoom range of the Sony+18-250 or Pentax+18-250.

You could just continue to use your 28-200mm, whichever you find
sharper, on a new Canon 400D with 18-55mm kit zoom lens, or maybe no kit
lens, and use the saving to buy a Tokina 12-24mm wide angle zoom (or
Canon, Tamron, Sigma of similar range). You would have two lenses then,
and although 200mm is similar to using a 320mm on full frame, as long as
you aware of the very real risks of camera shake and switch to higher
ISOs and faster shutter speeds, you should be OK. The old superzoom may
not be as good on the digital format as a new purpose-made design though.

Our daughter's Canon kit has a 400D with the kit 18-55mm and an early
(secondhand) Canon image stabilised 70-300mm covering the tele end,
where the IS stabilisation is extremely beneficial. Now if you can do a
search and hunt down such a lens that's a reasonable kit. I do not
advice the closest thing Canon has a stabilised superzoom, the full
frame 28-135mm IS. It's neither fish nor fowl when used on the smaller
digital format, and it's not much better than independent brand optics
either.

David

Rick,

I did the same thing with almost the same budget and after a great
deal of research settled on the Nikon D40 and Nikon 18-200 VR lens on
the advice of this website http://www.kenrockwell.com/nikon/d40.htm.
The camera comes with an 18-55 kit lens (It's very good) for about
£300 - it comes with a battery and charger - but there may well be a
seller who does body only. I bought the Nikon 18-200VR lens for £420
from an Amazon trader last  November so I suspect it will be cheaper
now. You will need to buy a memory card. I've been very pleased with
the set up and it's the best compromise I found.

Malcolm