We don't really have any. The Middle school next door to mine has a lab with 20" iMacs and they're ordering some AlumiMacs. They also have some powermacs and iMac G4's.
My school has all HP/Compaq computers. The oldest ones are maybe 4 years old. The newest ones have 17" adjustable LCD monitors, Core Duo Processors, 2gb Ram, pretty good video cards (512mb), 80gb HD's (all files are saved on servers). There are also some Laptops that teachers have... that they're not allowed to take out of school (I know, it makes sense). Some of the administrators have Tablet PC's.
Every classroom has 1 computer. Science rooms have about 9 computers, there are 6 Labs in the school with about 25 computers, SPED rooms usually have 4 or 5.
I'd like to see macs again, especially in the A/V / Graphic Design Lab lab.