Zip down Rt. 93 and share a unique day with your kids.  Enhance your stay and welcome spring with a visit to the Butterfly Exhibit, or relax in the Omni Theatre.  Current shows include Grand Canyon Adventure and  Schackleton's Antarctic Adventure.  Also showing, to get you bikers ready for snowless roads, is Wired to Win - Surviving the Tour de France.  Feel like an evening out?  Catch dinner in the city, and pop in for a late night U2 or Zeppelin laser show.  2 Exhibit Halls passes to the Museum of Science, Boston.   Expire February 1, 2009