Technical sales (or Sales Engineer) work can vary a lot. If you're working for a regional VAR much of your interaction may be on the phone, but working for an Enterprise Software vendor you'll often find yourself on a plane heading to and from the customer's location to gather requirements and make presentations in person. YMMV.

BTW, you might also consider working for one of the big consulting outfits, especially if travel is appealing to you, as an alternative to temporary contract work.