Free GM Resource: Map Tools
A few others managed to get together and cobble together some sort of Play-by-Post game, but these generally were not RPGs. Certainly there were some folks that managed to have a PbP RPG, but realistically this wasn't an option for the average player.
Fortunately technology has come a long way and PbP campaigns are possibly using virtual chat sessions or using a forum. I've been in a forum game that just hit the three year mark, which is a testament to the GM's abilities to keep things going.
Another option for gaming is to use what is known as a Virtual Table Top (VTT). There are a number of VTT programs out there to facilitate having a "local group" made up of people from just about anywhere in the world. If you have a good internet connection you can get a game on. There are a whole slew of VTT options, and I've tried several.
Most VTT programs are paid software that allows for a GM to run a game and have a certain number of players connected in. If you want more players you simply need to purchase more licenses. Sometimes the licenses seem a little steep, but they are like core rulebooks. If you get a good one that meets your needs, you'll use it often enough that the cost shouldn't be a factor. I have no qualms about shelling out $20-$800 for good software if it means I'll be getting my money's worth. The Frugal GM isn't about being cheap, it is about getting good use out of your available resources.
MapTools. The big difference between MapTools and a lot of the other offerings out there is the price and some bells and whistles. The last VTT I used was full of bells and whistles. It had gorgeous dice effects and the table top was highly customizable. I probably spent 40 hours designing a beautiful custom desktop, but in the end I considered that $40 and 40 hours a wash because we had too many problems getting players connected to the game. Even though a new version of that software came out, we migrated over to MapTools.
There isn't a lot to the default MapTools configuration. The real strength to the program is that is is highly customizable as well, but more from a functionality standpoint than a simply visual aesthetic. There are "frameworks" which can extend specific game rules into the program to make it easier to run a game, but if all you need to do is get players connected and share a map, then you will be set right off the bat. Being able to use the program to chat or roll dice is just a bonus. I play in a weekly game online using MapTools and our group supplements the virtual table with audio using a Ventrillo server. We've also used Skype as a free alternative, but Ventrillo is inexpensive and offered more flexibility.
I'm always looking for new things to make running a RPG game easier and/or more enjoyable. There are some new VTTs coming onto the market that I plan on checking out, but for now I highly recommend MapTools. If you need a brief tutorial on getting MapTools downloaded and a new game set-up, here are two posts I wrote up years ago (but are still relevant):
MapTools Part I (Installation)
MapTools Part II (Getting Connected)