Windows are pretty cheap and easy to install. The lights are pretty expensive though. The best deal I have found is a window kit for $9 +$5 S&H here:
I added a 4 small lights I got from Radeo Shack for $4 total. They work pretty good to light the case in dim lighting, but that is it (plus half of them burned out in about 6 months). I cut the hole with a jig-saw. Pretty easy and took only about 30 minutes to do. I have the same window kit in both of my computers, but I added a blowhole in one window with an 80mm fan and a chrome fan guard (purchased at same website for $3 and $1.75).
Windows on computers get lots of attension from most people. They just look cool. The only problem is you must clean the dust out regularely.
AthlonXP 1600+ 1.65v 42'C
FOP32-1 Mod w/80mm 30db
Epox 8KHA+ KT266A
256MB Crucial DDR266 cas2
GeForce2 GTS (210/410)
Sound Blaster Audigy
Antec SX-630 Case (mod'd)
TTGI TT-350-SS 370w PS
AMD Phenom II x4 945 3Ghz | ASUS M4A77TD | 2X WD 1TB SATA 2 hard drive | 2x2GB Corsair XMS3 | nVidia GeForce 8800 GTS | ATI TV Wonder Theater Pro 550 | Antec P-160 case | Antec 650w Earth Watts | LG Blu-ray Super Drive | LG DVD RW | Windows 7 Pro