This is my third trip to DC and am interested in doing a bit of shopping this time. I read in one of the guide books that the Eastern Market has a flea market on the weekends. Is it worth the time? Any suggestions or pros/cons?

Tia

Plenty of people in the DC area really like it. There are vendors for fresh fruit, flowers, veggies, meats, jewelry, photographs, etc. If this were your first trip to DC I'd say not to go (in favor of some more traditional DC sights), but since you've been to DC before you're probably at the stage for going to the less touristy, more local favorite places. For example, if you haven't been there already, try going out to Haines Point to see the Awakening statue or going to Great Falls park.

Here's the official E.M. website so you can see for yourself what it's like:
http://www.easternmarket.net

I enjoy going to the Eastern Market, especially if the weather is nice. You can find some unique items there. I took a friend (born/raised in Alabama) there when he visited, and he found a 1909 map of the State of Alabama. Of course, he bought it and had it framed.

The neighborhood itself is interesting, with a few coffeehouses, etc. I think the market is around 7th and Pennsylvania SE. If you head towards the Capitol on Penn to around 3rd St, there are several bars that cater to Capitol Hill employees, and are fun to go to and see all of the Congressional staffers and interns. Politiki, Bullfeathers, and Hawk and Dove are three of the more popular ones. Hawk and Dove was voted the "Best Place to Talk Politics" in the Washington Post.

Eastern Market is great. Weekends (daytime) is the best time to go to see all of the artists' and craftmans stands. The 'flea market' across 7th street from the food market has a large proportion of artists sell their stuff as well (paintings, sculpture, jewelry, craft furniture, photography, rare books, pottery, glassware, etc.) Eastern Market is actually considered all of 7th st between Penn. Ave and North Carolina Ave. Many restaurants there but the best is Montmarte. Make a reservation: 327 Seventh St. SE Washington, DC 202-544-1244. Eastern Market also has one of the best antique shops anywhere. And don't miss the market itself, the cheese guy alone has more cheeses than most parisian cheese shops. Have fun (and pray for sunny weather).

Is it metro accessible?

Yup, the orange and blue lines got to the "Eastern Market" Metro station. There are signs from there pointing to the market.