I've been doing a *lot* of travel the last couple of years: taking advantage of my stay in the UK to see as much of Europe as I can before I have to head home to Aus.
Mostly I've been traveling on cheap airlines or even driving. However, I've just joined a website that helps you collect airmiles at a much increased rate. They guarantee that you'll gather a minimum of 100,000 airmiles a year (even if you aren't based in the USA) which adds up to at least one significant trip each year.
They find the deals for you and list them on the member homepage, and you then go and collect your points and mark them "done". The claim being that you only need to spend half an hour each month gathering your points. Seems fairly good so far, but I'll let you know as I go along if I think it's worth it.
If you're interested, click on the linked image below.