I'm leaving for London in 3 weeks to visit my g/f who's working at an internship there for a few months. While I'm there we'll also be going to Amsterdam for a few days and doing all of the touristy stuff she's been saving for when I come visit. Right now all I have is my XSi and the 50mm f/1.8, no kit lens, and while I can afford to buy a lens right now, I couldn't comfortably do so and potentially rent another. I know I'll definitely need a wide angle, so I'm debating between the Tokina 11-16 and the Canon 10-22. My real problem is whether I should rent a 17-55(or 50) f/2.8, or get the 70-200 f/2.8L. I'm just not sure how much use I'd get out of the 70-200, and I'd have to depend on my 50mm for the entire 23-69mm focal range.