The most interesting thing about Tampa is its history, especially as it relates to Ybor City, a very unusual city within a city which is not to be missed.  If you visit Tampa, you've got to go to Ybor and have lunch at the Columbia and buy a cigar. 

Channelside Watersports and Fun Center rents Boats, Jet Skis, Motor Scooters and Electric Bikes for self guded tours all about Ybor City and the Channelside District. They are located at the end of 7th Ave at the The Heights of Tampa. Just Twist -N- Go... 
Channelside Watersports Rentals Take Tampa's Twist-N-Go Scooter Tour!

Fossil Expeditions - About 1.5 hours outside of Tampa, knowledgeable (and funny) guide Mark Renz leads a unique adventure.    www.fossilexpeditions.com

St Petersburg - downtown and the Pier, the beaches, St Petersurg Museum of Art. Lots of little shops, restaurants and bars. Nice easy day trip from anywhere in Tampa. Just across the bay.

Clearwater - beaches.  Across the bay a bit north of St Pete.

Tarpon Springs - the Pier and sponge divers, greek community, good food. An interesting afternoon trip about 45 minutes from central Tampa.

Cypress Gardens http://cypressgardens.com/welcome.asp

Bok Tower - landscaped gardens, lush lawns for picnics, the carillon (bell) tower, open air concerts.  http://www.boksanctuary.org/index.html

Sebring (for race car fans) in March.

Sarasota - Ringling Museum of Art, and circus museum. http://www.ringling.org/

AirHeads Trampoline Arena is a cool place to check out in Tampa- great fun for the whole family at a good price. Go play a game of trampoline dodgeball or just spend your day jumping!