Any good, cheap sources for concealing cables? I'm not going to run them through the wall, I just want something that mounts to the wall and runs about 4 ft, down to the floor, that I can tuck the cables into.

Check your local electrical supply houses for "wiring duct". It's made in slotted for wire breakout applications or solid for point to point wire routing. You want the solid. It comes in many sizes to accomodate just a few or many wires. The biggest manufacturer is Panduit, but there are several others. Home Depot carried some once upon a time, but I don't know if they still do.

I've purchased Wiremold brand cord cover at Lowe's recently. So, I expect that Home would have something similar.