There's a new style of RGB Strip LED now, with an embedded controller chip in each LED - the WS2812B!
Note: Discontinued, and replaced by the 60556
We've been fans of the standard Stripxel design that uses the good 'ol WS2801 IC, but like anything else, life is about change, and the WS2801 is seeing some competition from it's big brother, the WS2811. Well, the chip is the WS2811, but the real secret in the sauce is when you combine the chip into an RGB LED, you get the WS2812B LED. This is where things get cool!
Where the old Stripxel uses a 4-wire hookup (power/ground/data/clock), the new ones use only 3 (power/ground/data). A 50uS pause on the data line causes all the pixels to latch into their new color assignment.
And again, the wonderful coders at Adafruit have already created a Arduino library for these (Neopixels), or try your hand using the FastSPI libraries. If you lean more towards the Teensy 3.1, they've generated very impressive libraries for the WS2811/12B. There's even some hand-coded 8MHz AVR libraries.
Be aware that these are sold in 1 meter (3.3ft) sections. If you buy less than a full roll, you are not guaranteed to have connectors included. Just so you know...