Please Help! My truck won't start sometimes!

[TIMSPEED]

I went out last night, and the truck would NOT start (did this same thing the other day) So, unfortunately I had to leave it parked outside all night. But here's the kicker, when I went out to start it in the morning, it fired right up. Any ideas why it's doing this? I'm DEFINATELY getting fuel, but I'm not getting any spark. (It was dark outside, so I had the oppurtunity to see if there was spark in the spark plug boot. Every piece of my motor/ignition is brand new. Should I just buy a new Cap/Rotor/Coil & Module? (I was going to do it anyway)
It's just strange how it doesn't start, then after a few hours, it does. BTW: The truck had been sitting for about 5 hours when I couldn't start it last night.
HOPEFULLY the truck will start when I go to go out to lunch and home from work today! KNOCK ON WOOD!!