Been meaning to mention this David Bach article about volunteer vacations because it is a very cool idea, whether you are alone or with a group/family.

Instead of just hanging at the beach, you build your vacation around a volunteer opportunity. That doesn't have to mean forgoing France for a week dishing ham slices at a soup kitchen (although I can tell you this can be very rewarding--and darn interesting--as well).

Bach offers a bunch of suggestions, from whale expeditions to Habitat for Humanity, so you can just read the article for them. I'm looking at the American Hiking Society Volunteer Vacations, which are fairly cheap and look like fun.

Some of these things are extremely cheap, and I agree with Bach that the rewards of doing them are great -- the experiences you remember most and get the most out of are more often ones in which you are actively accomplishing something versus passively sunbathing. (Not to diss sunbathing; we all need a nap next to the ocean once in a while.)

Not all of these are necessarily financial deals, however. You generally have to pay something, and the more specialized the trip, the more you'll pay. (The whale trip for instance is about $2000 per person for a week. You really gotta love your whales to pay that much.)

Whether you go cheap or are willing to pay, though, the point is that doing something different, something that involves your mind and body and maybe has you working closely with family members in an unfamiliar setting--that's a vacation you'll remember. As Bach says, you may never want to go back to a "regular" vacation again.