For future reference. The wallwart JDFan links to looks similar to the 5v-ish wallwarts used on cell phones. Best to avoid them unless you know your stuff. Hint: You know your stuff when you don't have to ask. No, I usually have to ask.
Many of these 5v or so wallwarts have A) have piss poor power regulation, showing something like 10v on a voltmeter then slumping by as much as half when you approach their rated amperage. These suck ass because as you hit their rating I've rarely seen it put out 5v. Or B) the power rail is incredibly dirty. This is common with USB chargers. USB spec has loose requirements so a lot of companies cut corners. Some so much so that you'll get as much as the barest regulated 12v or more from one depending on the resistance of the wire to cut the voltage. Pure crap.... worse... you'll find warts that both problems. Throw any of those you find away, don't even use them for spare parts.
9v and 12v have crap wallwarts but I find more good than bad ones. The 5v power market is saturated with pure crap. I quit using the to power even my 3.3v projects.
Do you want the lights to just be on or do you want them to blink or change in any way?
If you want them to change, then you'd probably want to look at an LED-Wiz or a PacLED64 in combination with something like LED Blinky to drive them.
Did the OP say he was using a PC? I thought this was a standalone necessitating the need for a microcontroller like AVR, PIC or ARM.