We met a lot of wonderful and helpful people on our trip to Arequipa this weekend and saw lots of awesome things. So if you ever go to Arequipa, you should check out:
Bothy Hostel - They told us they just moved to a new location. I really liked it and they were very helpful and accomodating. (Please note, this is a hostel, not a hotel. Good for college students, perhaps not everyone.)
Pablo Tours - We found them in the LonelyPlanet travel guide and they were awesome. We even met Pablo himself and he led us down the canyon and through the crazy rain and darkness. Both the Oasis and the Valle de Fuego hostal had good food. If you want a planned tour of the Arequipa/Colca Canyon area, they can do it.
Inkawasi - A little restaurant in the Arequipa Plaza de Armas with delicious sandwiches and huge, delicious beverages. (Including lemonade that tastes like actual lemon, not lime)
Ice Palace - A little ice cream/dessert place around the corner from the plaza, across from the Iglesia de la Compania. Peruvian Airlines - They don't charge foreigners more than Peruvians. And they feed you tasty sandwiches on a 1 hour flight.
Monasterio Santa Catalina - It's worth the entrance fee. The inside is really neat and pretty. I don't know about the tour because we decided to wander around ourselves.
Plaza de Armas and nearby churches in the morning - I enjoyed walking around at 7 in the morning more than at 9. Less things open meant less people around.
Hopefully some day you do get to go to Arequipa. It's worth it!