My advice, leave ASAP! I kid... Or do I? Since that is not an option, I would suggest cab'ing it over to Harvard Square and drinking cheap:
http://www.yelp.com/search?find_desc=Cheap+Drinks&find_loc=Boston%2C+MA&cflt=pubs
Dinner in the Little Italy section called the North End. There is a bakery there with fantastic canollis and a bottle shop with fabulous selections of limoncello. Faneuil Hall is nice but touristy. Boston Common is an awesome site and the Bull and Finch is there as well. Also, the Sam Adams Brewery has tours and a tasting room. If you like dim sum then go to:
Empire Garden Restaurant
(617) 482-8898
690 Washington St
Plenty of food, cheap!!! There aren't bad bars over by BU either. For dinner, I also recommend Lucky's Lounge. Young crowd, great food. I went to college with the chef/manager.
http://boston.citysearch.com/profile/11475316 It's like a place out of
Swingers.
Boston is the most European city we have in the states. I love going there each June. The train can get you anywhere and a cab can always get you closer.
Also, if you travel a lot for work (I do 200+ days a years on the road), I like to use United's [url]Hemispheres[/url] magazine for suggestions. Each month the magazine has a Three Perfect Days travelogue.
http://www.hemispheresmagazine.com/3pd/three/2007/boston/
If you need anymore suggestions, for Boston or other towns, just PM me.