It's probably crazy and definitely different than most people here use miles for, but I use my miles for family tickets domestically. In laws and parents are both snowbirds, and either the whole family (for my parents) or the whole family except me (in laws) head south anywhere from 1-3 times per year for a while. At least, until the kids are in school anyway.

Depending on who we're seeing, tickets are either $300-$400 each or $600-700 each, and since we have flexibility, spending 25K miles is a great way to do it. The whole trip ends up costing very little, and for us, that's the best use of miles.

Oh yeah, and Mrs. Traveling Man and I did go first class to the Caribbean last year. Definitely a good use of miles!!