i don't know much about DSLR cameras so need some help:

Looking to get my girlfriend a filter lens (i think?) for christmas for her recently purchased Canon rebel xs (http://www.amazon.com/Canon-XS-Digit...1048412&sr=1-1)

according to the amazon recommended accessories, it looks like the size needed is 58mm - please correct me if i'm wrong. the one under recommended accessories does not have great reviews. I guess i want one that protects from UV and also filters out glare when shooting at a light source.

Not trying to break the bank here, this was going to be more of a 'stocking stuffer' type gift. Anyone have any suggestions?

Also, does the lens cap still snap on over this? or does the lens cap and filter lens have to be swapped out in order to use both?

thanks!