Malta isn't the most exciting locale in the Mediterranean, but it has its charms. Here are some suggestions (some repetition of items posted earlier):

Main island:
* Hagar Qim ruins are a must-see; the other ruins are interesting
* take a boat cruise
* visit the Palace of the Grand Masters
* visit the walled town of Mdina
* St. Paul's Bay has a nice feel to it
* linger over a drink at the Communist Party bar in Valleta (on the main drag, second floor)
* ride the buses, photograph the cars (similar to Cuba, except you'll see old British gems)

Gozo:
* consider staying at L-Imgarr Hotel or Ta' Cenc
* rent a 4WD and explore the island's dirt roads (watch out for goats!) There's little traffic on Gozo, so if you're uneasy about driving left, it's not as risky as the main island. I doubt you'll find an automatic, though, if that's a problem...
* spend an afternoon hanging out at a cafe on Victoria's main square
* have a drink at the fisherman's pub at Mgarr Harbor, near the ferry dock (sorry, don't remember the name: it may be Fisherman's Bar)
* buy a bottle of local wine; there's a great liquor store on Victoria's main square (if my memory is correct)
* visit the ruins at Xaghra
* the island is quiet midweek but is often flooded by main-islanders on weekends

Food and Drink
* The cuisine isn't notable (British influence?): fish, pasta, and pizza are the safest bets. I remember having a nice lunch at the Lantern (20 Sappers Street, Valleta)
* The shandy is the perfect beverage for Malta; good local beers (e.g., Cisk); try Tamakari once; Gozo wines are a hoot, resembling homemade
* gelato (needless to say)

On the plane:
* read Pynchon's V., which is set, in part, in Valletta. (Perhaps you'll run into pynchonesque in Malta?)

Have a safe journey and enjoy the experience!