I know its somewhat loaded being in the cross forum but I ahve been thinking of a second bike for commuting, fire-roads/trail and cross races just for kicks.
I'm thinking single speed.

I have a geared cross bike I ride/race/commute etc. I also have a road bike which I'll leave as is (but only sees weekend use). I have a full suspension 26" MTB that gets no use now so I'd like to use what I can from that, get rid of it and get something that I can have fun with. I just don't care for the MTB.

So what might be a better option?
SS 29r? Ride trails, could still commute on it and even hit a SS cross race.
SS Cross bike? Same handling, parts compatibility, right for cross but maybe lighter than a real trail bike.

Still on a budget