I'm making a little robot car. It's a piece of crap. So far, I can make it turn, go foward, and go backward. It's controlled my a programmable microcontroller. I've added a bumper with buttons so it'll know if it hits something in the front. It measures about 5 inches wide, a foot long, and 3 inches tall. It is controlled by two wheels in the back, with 2 seperate motors. They can be foward, backwards, or off. There is a third free spinning wheel in the front.

Keep in mind: My programming, electrical, and mechanical skills leave much to be admired, but I am decent and am willing to learn. I also can't spend much money, and don't have the greatest stockpile of materials, but I get by and have some things.

What should I make it do? Throw out some ideas, I'll tell you if they're too hard or (I wish) too easy.

a steering assembly,
It's a must

Mini turret.
LEDs and light sensors for line following.
Lasers. Everything is better with lasers.
Speakers hooked to an old mp3 player, which of course is controlled by the microcontroller. It can 'say' different things depending on the stimulus. Bonus points if it has HAL 9000's voice.
Self-destruct mode.
Bottle rockets.
Flamethrower made from a butane lighter.
Coilgun.

You may lose track of where it is easily. I recommend a beeper that beeps every few seconds so you know where it is.

a steering assembly,
It's a must

meh, not necessary. It steers fine with it's two motors.

You may lose track of where it is easily. I recommend a beeper that beeps every few seconds so you know where it is.

Good idea! Done.

Mini turret.
LEDs and light sensors for line following.
Lasers. Everything is better with lasers.
Speakers hooked to an old mp3 player, which of course is controlled by the microcontroller. It can 'say' different things depending on the stimulus. Bonus points if it has HAL 9000's voice.
Self-destruct mode.
Bottle rockets.
Flamethrower made from a butane lighter.
Coilgun.

You...of course, you. Hmmm what could the turret shoot? Lasers, nah. Line following...I should read up on that. Haha self destruct mode...

You may lose track of where it is easily. I recommend a beeper that beeps every few seconds so you know where it is.

Like an 'Everything is Okay' alarm. Nice.

Like an 'Everything is Okay' alarm. Nice.

Yeah. It has to be annoying,.

try this (http://www.totse.com/en/bad_ideas/ka_fucking_boom/detonate.html)