From left to right we have:

Daniel wearing a borrowed kilt. (not an xmarks member yet but
I understand he ordered his first kilt when he got back from the games yesterday)

Barclay, Tartan Hiker, Kiltedmusiclover, MacWage, and Brett(Nixphotography)
who hopes to be kilted in the future.

(Hamish I apologize now. as I think I will get the award for worst attempt ever at the Hamish pose)