not as familiar with this "off camera flash" type stuff yet. trying to figure out how i'd go about using off camera flash setup's to catch impromptu shots of friends/relatives/kids while meandering around at birthday parties and social gatherings.....?? not saying it's a bad idea, i'm not just practiced at it (haven't ever done it).
There are several ways of going off camera:
- Get a off camera cord and hold the flash away from the camera while flashing (and/or a bracket)
- Get a ST-E2 or 580EX/550EX or Flash that can act as a master and have a buddy (or flash stand) somewhere with a 430 or other flash slave (with a umbrella or somplace to bounce)
- Use your built-in flash or 430 to trigger an optical slave flash that is held by your buddy (or flash stand)
- etc.
The 1st is probably the easiest to do in impromptu settings. Overall, unless you're hired to do a venue its kinda impractical for social gatherings, IMHO.
If you had a Nikon with flash commander builtin, then you just need a slave flash 
yes, already have the 1.8 (see my sig line..... although maybe i didn't type it in there correctly, lol). great lens. but there's times when i wish i could zoom in or out rather than reposition myself 20 feet back.

I'd also second a fast f/2.8 wide lens. But, if you're shooting at f/2.8 (or faster with a prime) make sure you get the group of people parallel to each and shoot perpendicular to them to get them all in focus 
and now we get to the part where you HATE THIS LENS. zoiks. not sure i had heard anyone have such harsh things to say about this lens up until now. hunting? yeah, not fun. i've dealt with that on some other canon lenses in low light. lack of usm? no experience, but don't think it would totally bug me.
If you do a search on Marloon's posts, he's particularly opinionated about his dissatisfaction with his copy of the Tamron 17-50. If you do a search on any of the popular lenses, the Tamron 17-50, Sigma 18-50 Macro/No Macro, Canon 17-55 f/2.8 IS, you'll find a percentage of vocal, unhappy people. Now if *everyone* had the same opinion, you'd have cause to worry, but they're a minority.
The 17-50 is a great lens. It hunts no worse than the Canon 17-55 f/2.8. The AF motor speed is average, not as fast as the 17-55's USM.

lol

