Just back from Sikhay restaurant in Fort Worth (28th St). The real deal, as far is it goes -- best Lao food I've had in the USA. Very good beef laap, appropriately using plenty of offal and squiggly beef parts, although it could have used more spice (and I loved that they asked if I wanted it cooked or raw, rather than assume gringos have to have it cooked). One of the few places I've seen willing to serve Lao-style papaya salad without being asked -- crab, very pungent pla raa. Plentiful sticky rice.
Only downside is there are only a few Lao dishes; the rest is mostly Thai noodles and two curries, and some Chinese-American dishes (e.g., pepper steak). But the pad see ew with chicken was also the best pad see ew I've had in the US--really excellently charred and coated but not drowned in the soy sauce. The chicken pad gaprow used a good amount of good basil, and we had asked for it not too spicy since one of the kids wanted it that way, but it otherwise had some more Chinese-stir fry elements.
In short, REALLY worth seeking out in Fort Worth if you want some good laap and som tam. And just down the road on Belknap, I think, is an awesome Vietnamese supermarket with a far better produce and herb selection than I've seen in NYC Asian supermarkets.