Peter Hamm , Jun 12, 2011; 05:53 p.m.
The 11-16 is one of my favorite lenses I've ever owned, and yet even then I use it for a ridiculously small percentage of my actual photography. And it is specifically bad, imho, for "people photography" as perspective distortion tends to make people look really weird with a lens that wide.
The 17-55 is way more useful to you I would think.
If budget is really tight, for the price of the 17-55 you could get the 11-16 AND the highly regarded Tamron 17-50 f2.8.