You can visit Internet Cafe’s all around the world, patronize the establishment or somehow attain the login information without a purchase (we do the former, getting ourselves a much deserved treat).
In the States we bought 4G thru Verizon on a pay-as-you-go sort of plan. We purchase so many gigs and when it runs out we put more money down on it and go again with more gigs. We use free wifi when available at laundramats or coffee shops instead of our own as long as it isn’t anything private like banking and such. We only do that on our own secure connection.
What we have done in Mexico is to purchase a TelCel USB for an initial purchase of $25 and an additional $200 pesos (<$16) for 1GB to use within a month. The package we have is Banda Ancha Movil, whatever that actually means we aren’t sure since we aren’t proficient with our Spanish and the TelCel staff are not proficient with English so we have never fully understood what it is we have purchased. Overall it has worked for us, keeping us in touch with our daughters via Skype, Danaka connected with online friends, enabling me to post to this blog, and lets us do some research when necessary.
Our understanding is that if we don’t use the TelCel USB for more than 6 months than our account will become inactive. Whatever balance we might have on the account will be accessible once we put even just a few dollars down on the stagnant account and it will be active once again.