i suggest you let her know you're interested in a very casual off-hand sort of way, in which case it should be a lot less awkward if she doesnt reciprocate you're feelings. As a female that tends to have male friends, i can tell you that many females as such are happy to keep being friends with guys that have confessed to them...the onl issue is avoiding any major initial awkwardness.

>>2 the 'friend zone' isn't as much of an obstacle as a lot of guys seem to think. often it isn't an obstacle at least... many women feel that being friend with someone first is very much prefferable to just meeting some random guy.
girls who like having male friends generaly try to make friends with ones they think are good loking, or at least somewhat good looking, since its more fun than being freinds with a bunch of ugly losers. ie the girl probably thinks at least some of her male friends are hot. girls avoid being friens with guys they think are totaly gross.
also, i, and the other girls i know who tend to hang out wth guys rather than a bunch of other girls are often interested in one of those friends, or at least thinking 'hmmn, if [instert name] were to ask me out, that would be cool' and we wonder things like 'i wonder how many of my male friends think im hot?' or 'are any of these guys interested in me?'

here is a strategy to help determine whether confessing your feelings to a female friend would be a good idea or not. i know it can work, because it was used on me by my last boyfriend lol
first make sure you're talking about relationships or taste or something that won't make the question seem surprising to be suddenly asked. then, you say some thing like 'hey, [insert name of other male friend here] and i were aguing/talking [or something] the other night about which one of us is more your type/ you'd be more likely to be interested in [something like that] ?'
her response should hopefully give you a good idea about how interested in you she might be. even if she says its you in a seemingly joking way, its still a pretty good sign. if there's any blushing involved, she's yours lol. as long as she doenst say the other guy lol