The uilleann pipe (pictured above) is the Irish bagpipe. In Irish, the word 'uilleann' means elbow - the uilleann pipe is attached at the elbow, and is bellows-driven, rather than blown into (like the highland bagpipe). Some uilleann pipes are larger than the one Neil uses, with a long pipe attached, like the one Davy Spillane plays (he performed an uilleann pipe solo in the Dublin production of Riverdance). Neil plays with a lot of heart - The Washington Times called him the "Jimi Hendrix of the highland bagpipe."
Right and below are Neil at the Scottish & Irish Music Festival in King of Prussia, Pennsylvania, playing in the band Rathkeltair.