Help getting a shot of 7 people standing shouler to shoulder?

I have a Nikon D90. Normally I do nature, but have been asked to get an outdoor shot of seven people standing shoulder to shoulder.

Should I use my 10-20 wide angle lens for this shot? I also have a 50mm 1.4 prime and the 18-55 kit lens.

And I'm thinking I'll need a fill flash too, yes?

Yes.use your 10 - 20 wide angle lens and i would say try fill flash. Stand back a good distance and shoot xD

I would use the 10-20 or the 18-55. And to have something that looks a little better than the boring shoulder to shoulder, have them stand at a bit of an angle. Use the lowest aperture to throw the background out of focus, and fill flash is never a bad thing. If you have at least the SB600, set it up off camera at a different angle from where you are shooting with CLS to fire it remotely. If you have only the built in, it should work great. Its always a good idea to take multiple pictures, as people have a nasty habbit of blinking.