Derived from an msn messenger emoticon, '(h)' denotes a round yellow face with black shades and a big white grin, what it of course also denotes is the quality of being good/cool/great often with some ebullience.
"I well got laid last night (h)"
The cool dude emoticon on MSN with teh shades - teh best emoticon EVER !!
Malcolm: DUDE !! you ROCK !!