I got them from various sellers on eBay...but all eBay.
I've ordered just the strips, then had to go back and order remotes + controllers.
I'd say pick up the complete set, RGB LED strip + remote + controll. Should come in at about $15-20 "Buy It Now."
I think buying part by part I perhaps saved $2-3, but you wait WEEKS !
So again..eBay, any seller really, and buy the complete kit.
The only application I've done (as of now) was take a strip of the lights and lay them accross the tops of my 4 Nintendo cabinets. The cabinets are side by side and it gives a great effect....I'll try and find a photo.
But I've seen people who wrap the base of the cabinet with the lights and that looks sweet. Even adding some to the back (which I cant cause most cabinets I own are missing the back door).
And to just repeat it, the 12" cold cathode tubes @ $10 on eBay are super cool. 2 x 12" tubes cost me $10-12. They get power from the 12v of your power supply. For my Bad Dudes I installed the one as shown, then ended up breaking one

---------- Had I not I would have put it on the back of the cabinet for a cool effect.
I just think these little mods help provide a lil something extra.
Lastly I'll say this EL wire (powered via USB on your PC) sucks.............stuff is so dim!
I bought this to try working into a build, but it provides NO REAL LIGHT!