I've been doing surveys once a week (plus some special surveys) at http://opinionplace.com. Usually you get 75 AA miles for completing a 5-10 minute survey. I just try to fit it into my schedule like while I'm eating during lunch. I've also been doing http://e-miles.com since their surveys only take about 30 seconds (one page, 3-5 questions), can be completed on my smartphone and every 500 points can be transferred to AS for 500 miles. Many people might see this as a waste of time, but I've got some downtime occasionally and this is a painless way to use it productively. Let me know if you have any others you use.