Help on working out the abs

I do about 250 cross crunches twice a week, but what I'm trying to do is target all my abs with out going to the gym.
I need routines to work out my lower abs and my obliques cause I have my abdonimals all worked out.
So if your an expert on this...

please help,

running helps your abs too like if you suck in and hold your stomach in the whole time...and cross crunches just help the far side to make it look beastly, you have to do normal too...go out and buy a medicine ball about 8 pounds and do crunches with you holding it. it makes it a lot harder and you get abs a lot quicker

I use an ab roller and it works wonders =]

Also a yoga ball with give you more of a degree of stretching out and back in. I get almost nothing from the ground anymore so I have to pretty much use an incline bench or a yoga ball for any type of stomach exercise.