wireless Internet In Cuzco?

Just about every street in the centre has about 3 internet cafes with Windows XP and fast internet connections for 1 Sol per hour (about $0.40), CD burning options and USB ports. Some also have DVD burning options. I was always allowed to attach my own storage device (portable harddisk) or camera, and even use the power supply (to use electricity), I always asked beforehand.

In the evenings the internet cafes can be crowded with Peruvians using the internet (most of them don't have pc's at home).

You might want to bring your laptop if you prefer to work in the privacy of your own room (without internet probably, or you'd have to be in a fancy hotel). Obviously a laptop is a very popular target for thieves. Are you willing to take the risk? If so, at least get good travel insurance, and make regular back-ups of important files.

Also read the Computers, Cameras and Phones branch on the Thorn Tree, and www.kropla.com and www.adrianwarren.com.

Tons of internet places everywhere.

I'd leave the laptop at home, unless you have a laptop that can use 220v, otherwise you have to have a converter/adaptor.