I was out for supplies at Lowes, thinking about how I wanted to add light to my lower level, and I came across these LED strips. They have a sticky backing their entire length. The are expandable. The main kit with the power source and switch comes with two 18" strips, then you can get 12" add ons. The system says you can have 6 total strips joined together (2-18" and 4-12"). The down side was the plugs from one srtip to another, only 4" or directly back to back, but some 24ga wire solved that!
I really like the look, and they were fairly inexpensive, $25 for the main and $15 for the add on!
They put out a good amount of light, I put the 12's on the back side of the front frame facing the back, and the two 18's running width wise in the main areas.