Wow - pretty great deal:
Yongnuo 50mm f/1.8 lens for Canon for $50 at B&H.
The Canon (and Nikon) 50mm f/1.8 has long been the cheapest and simplest way to take your camera and kit lens to the next level. If you wan't to take portraits with lovely out of focus backgrounds, this is the lens for you. At around $100-120, they were always great value.
Some two years ago Yongnuo came out with this lens, and it's a near-perfect clone of the Canon. I've tested Yongnuo products extensively, and their quality is top-notch. Now I haven't used this lens myself (I shoot Nikon), but everything I've read says that it's pretty much exactly like the Canon.
Now, at fifty bucks, it's an absolute steal. If you have any canon DSLR and only the kit lens (or even if you have one of the cheaper teles as well (such as the 55-250),
this is an absolute no-brainer.