DECLARE @MaxThought INT;

SELECT @MaxThought = MAX(thoughtid) FROM TRP_thoughts;

SELECT * FROM TRP_thoughts WHERE thoughtid = FLOOR(RAND(CHECKSUM(NEWID()))*@MaxThought)+1;

Should get you a random row each time, and is more efficient than the usual TOP (1) ... ORDER BY NewID(). If there's gaps in the identity sequence you could end up not getting a row sometimes though.