Check all wires to the starter. There is a single small one that leads to...uhh something (I forget right now) that if it comes loose can play hell with you.

Is this consistent or intermittent at all?

I would be checking the plug wires for consistent spark as well, it happens sometimes that one will go bad. I would also pull the plugs and check the ends for carbon build up or oil etc. while there I would get a leakdown compression check as well. Simple to do and since you are in the neighborhood and all that.