I'm assuming you already have access to some sort of laptop/desktop to post to slashdot? I'd say skip the shields, get a cheap arduino clone, probably one with the USB port NOT the separate TTL programmer if this is your first Arduino experience. Don't forget a USB CABLE for it. Small breadboard, some suitable jumper wires, (or perhaps you can recycle some old cat5?) and a few cheap servos ($5 ea). No real need for a "shield", you can directly connect most servos. It's also quite easy to convert the servos to "continuous rotation" if you want a speed-controllable (propulsion) motor rather than a position-controllable (steering) one (assuming you also have access to some tiny screwdrivers, knife/clippers, etc). Recycle bits of spare wood/plastic/card for body, wheels, arms, whatever. You can make really simple sensors by just having INPUT_PULLUP wires touch GND wires when bumped. Servos can steer/push/pull/propel/twist things. You can LATER look at more reliable switches/buttons, light/IR/temperature/distance/other sensors, RGB LEDs, displays, WiFi, Bluetooth, etc once you've had a bit of fun and have a better idea what you want to build. Remember most Arduinos already have 1 status LED, and Serial.print() for debugging/control whilst still connected to USB.