Many if not most hotels, B&Bs and rentals in San Miguel offer free Wifi.

It is also possible to hook up for free on the north side of the main square (Jardín). Many cafes and restaurants have free Wifi available to their customers.  In some cases, you may have to ask a cafe employee for the password to connect to the internet. The Biblioteca now makes a small charge, whilst the dedicated internet cafes are all very reasonably priced and often have Skype.