Santiago isn't one of those "exciting" cities with a list of must-do attractions. That said, you will probably like it very much. I have been there many times, and will be there again next month.

Not knowing where you are staying, as long as you are not staying out in Las Condes, things are close and cabs are plentiful, safe, and cheap. Also, the Metro is very good, but doesn't run very late.

Dining - 2 barrios - Providencia and Bellavista. Food is generally inexpensive, fairly simple, and good. There are some very high end restaurants, but I've never been to one. In Bellavista last year, I had just an exceptional meal in an italian restaurant - I can't tell you the name, but it was next to a stylish seafood restaurant (I think that one is Azul Profundo, which also looks outstanding). That barrio also has lots of nightlife, etc. (as does Providencia). Both generally safe areas.

You should also check out the Mercado Central for a seafood lunch - stick to the restaurants on the fringes of the inside, not the one owned by the big company in the middle. Don't be afraid of everyone wanting you to come in and eat at their location. Everyone is really nice.

As far as sights on a short trip. you should go up Cerro San Cristobal on the funicular (which you catch in Bellavista) - there's a zoo up on the way, too. Not too impressive, except its on a hillside with a great view of the Andes (if it is clear).

You should also go down to La Moneda, and surrounds.

If you like the vino, check out Mundo del Vino. It is a great store in Las Condes (on Av. Isadora Goyenechea). Great knowledgeable staff, and a handful of samples, and reasonable prices. The street surrounding the place (Harbucks, Hooters, and other middle america drivel) will make you not too excited, culturally, but the store is worth the visit.

Disfrutelo!