With my Canon 30D, I also decided to buy a 50mm lens (mainly for the fact that it was the only other lens I could afford at this point in time). I wouldn't let the price fool you, it is a great lens. It works very well in low light and give you lots and lots of Bokeh. It's a simple and modest lens but that's what I like about it. There's not too much fuss but its gives unbelievable pictures. But let's move on to my obsession with Bokeh. If you don't know what that is, Wikipedia defines Bokeh as a word derived from the Japanese that is "a photographic term referring to the appearance of out-of-focus areas of an image produced by a camera lens."
And if words failed to explain what Bokeh is, here are some of my favorite Bokeh images that I found while wandering on Flickr:
"Golden Days" by moaan
"Bubble Blizzard Bokeh" by betie bet
"The Wishing Bokeh Fountain" by krashingmotions
"Cosmo & Bokeh = Love" by .kels. (a little busy)
"Mad Crazy Bokeh Tree" by Kristybee