I like the stretch of the W&OD from Herndon out towards ashburn. There's the Old Ox Brewery, what looks like a good barbecue place that has a mess of bicycles right by the trail a little further out, and, back towards Herndon, and Great Harvest and a nice bike shop with a coffee / smoothey / energy snack bar (Green Dragon or something like that). Sells pinarellos and asthma inhalers 
There are a couple of brew pubs in Sterling as well ... not too far off the trail. I always made a stop at Dominion back in the day.
Heads up, they're appropriating funds to erect a bike overpass at Sterling BLVD. There used to be a place at Ashburn RD (Partlows ?) that was pretty neat. It may have been been there in the RR days. I think they turned it into somekind of BBQ joint.
