I'm quite pleased with these two offerings from Lee Valley Tools (no affiliation). They hold up to real work, unlike other cheapies, and are standard carry-on kit whey I fly.

Edit: the red-handled version with the usual "paramedic shear" safety foot isn't in the catalogue any more. Too bad. But they're functionally identical.

http://www.leevalley.com/US/wood/page.aspx?p=59398&cat=1,64488