Joe's got it here. I look at it this way: I'd rather have to make a choice between two or more options rather than loading everything I got into one choice and hope that one works out for me.
Right now I'm in the process of applying/have applied for Navy OCS, 5 Air Guard units and the Active Duty AF. It's a lot of paper work, but it's generally all the same info. The real kickers are the Guard Units. You basically have to "pledge" them, which means going out there during their Drill weekends, meet all the guys, bring lots of booze and experience all the FNG stuff. It's a much different experience than trying to get into the others IMHO.