When I first used this lens, I was amazed at how Canon had managed to make it so noisy. I had known to expect it but was still surprised. What I'll also say is that, much like a ticking clock, you soon don't notice it, especially outdoors. Do not let it put you off buying one of these.
The virtues of this lens more than make up for the occasional buzz. It is small, light and cheap but is a real gem in terms of image quality, particularly its sharpness. F2 is good enough for indoor use without flash, anything above and is snaps into pin-sharpness.
It really is so good that you'll need something else pretty good to justify swapping lenses, even when a zoom is required. One reason not to bother is that it keeps your SLR about as light and compact as it can be and ideal for travelling.
It has become my walkabout lens on a 350D. If you require a zoom, you'll need a 17-40 F4L or 16-35 F2.8L to match or better this. Until you can afford one, use the foot zoom, it's more involving and kinda fun anyway.
If you were limited to just one lens, you'd have no complaint if it were this one. It opens up the possibility for everyone to own at least one good lens and shows just how bad the kit item is. Highly recommended.