I'm getting very excited for my Canon EF 100mm f/2.8L Macro IS USM (if you can't tell from me typing all the bits of the name). In preparation, I'd like to order a filter for added protection. It seems as though Hoya would be a suitable brand. Now the question is what filter. A UV filter seems to fit the bill for protection, but from what I understand it is useless for anything else. However, I can't think any other filter would be particularly useful for macro. Any thoughts?