That 24-85 looks tempting but when i looked closer at the specs i saw that it has a variable aperture for 2.8-4 which is not that bad but i like it to be constant. saw this tamron 28-75 that has a fixed f2.8 that looked like it was a nice price but used. dont know how you feel about used.
http://cgi.ebay.com/Tamron-28-75mm-f-2-8-SP-XR-ZL-Di-LD-Aspherical-IF-Lens-/390303674429?pt=Camera_Lenses&hash=item5adfe9703d
new you can get one for about $450.