I'm a bit of a noon when it comes to flash work, but I know the on camera is all but useless in most cases (unless I want to make people look terrible). Just sold my bike so have a wee bit of cash to play with. I want a flash I can bounce, and that I can use off-camera. I won't be doing any studio work or anything, I just want to be able to take pics at parties and make a lightbox etc. I shoot a 550d, what do people recommend for a modest first flash?