I really enjoy Geocaching.
It is like a scavenger hunt where the Latitude and Longitude coordinates are given on a website and a person must locate the Cache or treasure using a GPS. Once found a person may trade trinkets or simply sign the log book.
I like it because it gets me outside and makes me use my mind.
I do it all year round, even in the winter which can get pretty cold here in Maryland.
To find out more information about Geocaching...
Wendy's Comment: Thanks Ted! Sounds like a great hobby that I'm sure others will enjoy too!
Geocaching also sounds similar to Letterboxing... but there are funny little clues in Letterboxing instead of geo-coordinates. Still, it uses your brain power and is a hunt (and you also sign the small book in the letter boxes when you find them!) Links to Letterboxing clues (Bonnie, the writer of the article on my pen pal website, as well as other letterboxing websites and and clues worldwide!)