Well, I happened to have an opened bottle in the fridge of some verjuice that I bought at Pennsic from the Pepperer's Guild http://members.cox.net/periac/pepperers.html
Christopher and I also found some at his local Shop-rite (they were having a cheese tasting weekend) which had been ordered in from Maggie Beer (it's an australian vinyard): http://www.maggiebeer.com.au/ [They also have a book on verjuice: Maggie Beer's Cooking with Verjuice ISBN: 0-14-300091-8 RRP: $22.95]
Comparison note: the Pepperers' guild one is sweeter and more like a very light, somewhat tart white grape juice; Maggie Beer's has a more malic acid flavor, giving a flavor reminiscent of crab-apples, so it's tarter but still drinkable.
Verjuice
Christopher and I also found some at his local Shop-rite (they were having a cheese tasting weekend) which had been ordered in from Maggie Beer (it's an australian vinyard): http://www.maggiebeer.com.au/
[They also have a book on verjuice: Maggie Beer's Cooking with Verjuice ISBN: 0-14-300091-8 RRP: $22.95]
Comparison note: the Pepperers' guild one is sweeter and more like a very light, somewhat tart white grape juice; Maggie Beer's has a more malic acid flavor, giving a flavor reminiscent of crab-apples, so it's tarter but still drinkable.