For what it's worth (and as far as I'm aware), H1B visas are now capped (i.e. full) until October 1st, 2012 - applications are accepted from April 1st - so there may not be much sense in companies including the keyword "H1B" as requested, unless they're looking to fill a roll later in the year..
Ask HN: Who is Hiring? (January 2012)