This is gRover, the Grove-Platform Rover; it is a general, all-purpose rover for house exploration.

Foreword:

Components Used:
2 Motors
1 Touch Sensor (Mounted on RCX for Remote, Wired Control)

Required Parts:
RIS 1.0
Electrical Connector Plate (White, Comes With 9V Motor Set)

Description:
Moves from one end of the string to another. When it gets there, the touch sensor hits the wall, (Or whatever is used to hang it) and it reverses directions.

Well... What can I say? This is probably (I have yet to be proven wrong) - the LEGO Mindstorms' Community's First One-Legged Walker, and both simple and complex at the same time.

Components Used:
2 Motors
2 Touch Sensors
1 Light Sensor

Required Parts:
RIS 1.0
Parts from other LEGO Sets

Description:
Lil' Buggy can:
1) Dance to the Macarena
2) Run around a room by itself without bumping into anything
3) Play a game with you

Components Used:
2 Motors
2 Touch Sensors

Required Parts:
RIS 1.0

Description:
In essence, this is Dave Baum's BugBot, (No copyright infringement intended). I added an extra set of antennae (To be able to sense further up, so it wouldn't get stuck under the bottom of a chair, counter, etc). I also made the speed faster in the program so it can run around the room a little more efficiently.

Instructions:

Components Used:
2 Motors

Required Parts:
RIS 1.0
Parts from other LEGO Sets

Description:
There is one motor to move the whole arm up and down, and one motor to open and close the hand. Possible upgrades could include pneumatics to raise and lower or open and close the hand, rotating arm, maybe even wrist motion.

(This is an independent site not authorized or sponsored by the LEGO Group.)

Components Used:
2 Motors (1 for movement and 1 for possible add-ons)
2 Touch Sensors

Required Parts:
RIS 1.0
Strong string to hang it on

Description:
Moves from one end of the string to another. When it gets there, the touch sensor hits the wall, (Or whatever is used to hang it) and it reverses directions.

Instructions:
Instructions are in Aerial.pdf.
Aerial.pdf is (c) 2000 The LEGO Group

(This is an independent site not authorized or sponsored by the LEGO Group.)

Components Used:
2 Motors
1 Light Sensor

Required Parts:
RIS 1.0

Description:
The robot can either be used as a line follower or it can be used to spin aimlessly in circles (Woo!) if the light sensor arm is removed.

(This is an independent site not authorized or sponsored by the LEGO Group.)

Components Used:
2 Motors
1 Light Sensor
1 Touch Sensor

Required Parts:
RIS 1.0

Description:
The robot moves forward until it hits something, (The wheel is forced upwards enough to activate the touch sensor behind), then it moves backwards, turns slightly, and moves forwards again. It also has a light sensor on the back for line-following.

(This is an independent site not authorized or sponsored by the LEGO Group.)