Advice on calling US from Mexico

If you went to Mexico and called home how much did it cost?  Any tips on how to do this in an affordable way?  I am running out of money! Also, Do you know if my Ipod Touch will work to send emails?  I am pretty sure there will be WIFI available.
Thanks!

My phone worked in Mexico, but the roaming charges were kinda ridiculous. I have Verizon and I had no trouble at all making calls. I did call home alot though. I think they have WIFI at the hospital and hotel. When I would travel with Trish to the Dr.'s office they allowed me to use their office phone as much as I wanted. Next week is your big day! I'm happy for you! I pray that all goes well for you. Keep in touch!

If your staying at the hotel Lercerna you can use computer in your room. I bought a calling card from att to call hotel to speak to my daughter from the u.s.