I have signed up for the Continental eMailes Program, as I do just about anything I can to maximize my flight miles. This program is fairly simple: you sign up (100 miles) and on a frequency you choose, you are sent marketing messages that equate to flight miles.
Yeah, I know: boring marketing stuff… however, these are fairly painless. The result is that you build up miles very quickly. I set my account to only bug me with a message every 2 days via HTML email. They also ask you to specify the number of minutes that it takes, so it is easy to minimize the impact.
There are a lot of these programs, and they are not all created equally. I lean more towards the ones sponsored by the airline itself, and so far, this is a good one.
Feel free to chime in with your own experiences, links and other programs; the more we share about this stuff, the more miles we earn and that means free travel! -Editor