I love how this guys set out very specific guidelines to what he needed/wanted and everyone pretty much did not follow them whatsoever...
Everyone suggested primes (for the most part), those meet the price aspect, but definitely not the multipurpose requirement.
the 17-55 is 1000+, a far cry from the 550...
Again, read up on this 17-85, which is right at your price limit:
http://www.kenrockwell.com/canon/lenses/17-85-is.htm
http://www.the-digital-picture.com/Reviews/Canon-EF-S-17-85mm-f-4-5.6-IS-USM-Lens-Review.aspx
The 15-85 is viable too, but a few hundred out of your stated range:
http://www.the-digital-picture.com/Reviews/Canon-EF-S-15-85mm-f-3.5-5.6-IS-USM-Lens-Review.aspx
And for a longer range and still good IQ, the EF28-135, not the EFS. This is the lens I'd recommend the most to you, based on your specifications.
http://www.kenrockwell.com/canon/lenses/28-135mm.htm
http://www.the-digital-picture.com/Reviews/Canon-EF-28-135mm-f-3.5-5.6-IS-USM-Lens-Review.aspx
And don't be afraid to buy refurbished stuff. All of my equipment was purchased lightly used or refurb'd, and obviously I saved a fair amount of cash!
To buy:
http://www.adorama.com/searchsite/default.aspx?searchinfo=Canon+28-135mm+IS+
http://www.adorama.com/SearchSite/Default.aspx?searchinfo=Canon%20EF-S%2015-85mm%20f/3.5-5.6%20IS%20USM%20
http://www.adorama.com/SearchSite/Default.aspx?searchinfo=Canon%20EF-S%2017-85mm