I'm taking a short holiday in Mexico in a few weeks, and need to be able to dial in to tend my site. I'm thus looking for a local dial-in ISP, preferably free, but pay if necessary.

Does anyone have any ideas of where I can find one?

The potentials I have spotted always end up taking me down a blind alley. I just want to be able to dial-in a couple of times per day, locally instead of internationally.