but and energetic and rarin' to go? I found this blog post today that lists the "top" five trips for 50+ travelers. Who decides what's tops? You can decide whether it's just a sales pitch. But what I like about the groups they chose is that they're either active or educational.
The problem is, I don't view 50 as "old," or an indication that someone has slowed down. Nevermind. If you feel you ARE in that category - not old, but desiring a slower pace, perhaps - these are worth looking into.
The tour companies are Eldertreks, Walking the World ("for those who are 50 or better"), 50plus Expeditions, Senior Women's Travel by SWTTours and Smithsonian Journeys.