8a. Av 12-65 Zona 1
If you ever need a great place to stay in Guatemala City, check out the Spring Hotel (say O-tel Espring). It's in an interesting part of the city, away from the more touristy places, but near lots of great restaurants and, interestingly enough, right down the block from Casa Alianza.
Inside you'll find lots of expatriate hippies, former/current Peace Corps volunteers, and more Witness for Peace delegations than you can shake a stick at.
Rooms are a few US dollars/night (cheap enough that you can live there long-term), plus a few more if you want a private bathroom. I have to recommend the shared bathroom, though. You meet so many interesting people, like maybe some Swedish nursing students or an Italian opera singer or two (They were singing in the shower. It was so beautiful).
The best thing about the hotel is that it is filled with plants and banana trees and the roof is open in the middle in that Spanish courtyard-style architechture, giving it a soaring kind of greenhouse feeling. Sit in the courtyard, read a book, soak up the sun filtering in through the leaves, have some tea from the cafe and meet fascinating people who just might change your life.
I miss Guatemala so badly I could just cry.