Stomach exercises?

[owl]

I need to tone my stomach up for the summer, i was wondering what are some good stomach exercises?
I know that crunches are really good, any other suggestions?

[Turtle]

There's something called the 'Plank' which seems to be very popular in fitness mags right now. It seems to be a kind of controlled stationary push-up (does that make sense??) I tried it once and fell in a big heap after about a second, but it might be worth looking up?

[owl]

thanks, i'll look it up right now

[Metamorph]

Lie flat on your back and raise your feet about 6 inches off the floor while keeping legs straight. keep them there for a while and it'll really tense your stomach. obviously use a variety of exercises for best results. 

this is the plank on youtube

[James-Alen]

Man, those are hard. They made us do them in high school PE. I imagine it really does work you out though, it's like that motionless exercise stuff.

[Silver]

Leg lifts, those stupid "rowboat" things. Actually, I don't know what they're called but I think they were rowboats or something. You lie face up and lift your legs and upper body so you're sort of balancing on your butt and sort of twist from side to side. It's weird, but supposedly good for the obliques. Leg lifts are self-explanatory.