UV filter for my canon 400d

[r_j_k_p]

i recently discovered 2 or 3 large cracks in my UV filter (58mm) on my canon 400d. (the thing thats on the end of the lens)
i dont really understand what it does? so firstly if anyone could help me on that?

and secondly, can anyone point me in a direction to get a cheap new one, as i dont want my actual lens to get dusty or anything

many thanks

[Whiternoise]

ebay for a cheapo one? eBay.co.uk - 58mm UV, Digital Camera Accessories, Camera Lenses, Film Camera Accessories items at low prices

AFAIK, UV filters are fairly pointless these days and as you say, are good for keeping the lens clean. I presume they just filter out excess UV light so that you don't get as much glare? UV filter - Wikipedia, the free encyclopedia

[BUFF]

they are also largely used to prevent damage to the front element of your lens - better to replace a filter than a lens.