Our...
Favorite eats near the racecourse:
Wegman's 240 Nassau Park Blvd, Princeton
Wegman's is the most awesome grocery store I've ever been to.  It's offers tons of delicious, healthy prepared food bars that are great for a quick stop after practice. 

Romano's Macaroni Grill, 3569 US Highway 1, Princeton
Macaroni Grill's a good spot because it's big and can accomodate a team's worth of people.  The food's great and there's a wide variety of choices.  Bonus: they give you crayons so you can draw on the paper table clothes.

Good food closer to Princeton campus is limited.  Most of the students eat at their eating clubs so there isn't a great demand for the usual great cheap restaurants you would find in most college towns.  A few places hold there own:

Hoagie Haven, 242 Nassau St., Princeton
Probably the most popular take out place in Princeton.  They sell cold and hot Hoagies with pretty much anything you could imagine.  They're breakfast sandwiches are yummy as are some of their signature sandwiches: Phat Lady- should only be eaten post-row as it is a super cheesey cheese steak with mozzarella sticks and french fries... in it!  The heartstopper has cheese steak, bacon, and eggs!

Conte's Pizza, 339 Witherspoon St., Princeton
Conte's is a great place for larger groups to go out for dinner.  They specialize in thin crust pizza and offer a variety of salads.  They have a full bar which is rare in Princeton (and NJ).  Their prices are decent and the atmosphere's upbeat and fun.

Teresa's Caffe, 23 Palmer Square E
If you're looking for a smaller place to go to dinner and can spend a few extra dollars, Teresa's is where you want to go.  Sometimes you have to wait for a while, but their bread alone is worth it.  They offer a variety of upscale Italian dishes, and their pizzas are awesome!  It's a great place to go, especially if your parents are picking up the bill!

Food for Celebrating after the Regatta:
 

Triumph Brewery, 138 Nassau St., Princeton
Sometimes has legitimate live music.  They charge a $5 cover after 9pm. 

The Alchemist and Barrister (The A&B), 28 Witherspoon St., Princeton
Has outdoor seating and great fries!

To play and see:

I asked my friend who lives in Princeton for some help on this one.  Her response, "first off, if anyone finds any fun things in Princeton, I'd love to know!"  She then told me the following: If you have more time to actually do something, apple/fruit picking at Terhune Orchards is a fun outing.  It doesn't necessarily take that long.  When you get there they give you a bag and you get to go about the orchard filling it to your content and then you pay by the weight.  It's fun if you've never done anything like it and they have a cute little country store that sells freshly made doughnut holes and a variety of butters, jams, vegetables and pies if you are so inclined.  On a nice day it's fun to enjoy the out doors (with out having to get in a workout!)