We recommend the Hotel “Posada Señorial” because it is close to the conference and nice place. Some previous conferences took place in this hotel. More information (reviews and pictures) on it is found here. Information about other places also appears on this page. You can make reservations in http://www.posadasenorial.com/
There is another Hotel “Posada Señorial” in the historic downtown in Puebla, but you need to drive or take a cab and travel for about 40 to 50 minutes to get to UDLAP.
One place that I would like to stay is “Fiesta Americana Puebla”, very nice place close to UDLAP but you also need to drive. You can make reservations on here.
Another nice hotel is Radisson , but not as convenient as Fiesta Americana to get to UDLAP.