I've been using Careers from short time. I would like to suggest a new feature, if this is the right place. Some companies require their future employees to be available to travel for company missions; part of these companies (especially consulting) requires >60% of travel time. Some candidates are enthusiast at the idea of seeing new locations for work, paid meals and planes, while others have family and/or just hate planes.
The proposal is simple: allow employers to submit their offer with 3 options: little or no traveling required, large traveling required, and not specified of course.
The candidate can perform an advanced search and include only those jobs that match his/her travel wishes.
For example, I prefer frequent-traveling jobs (perhaps at the customer's offices) above always-on-site jobs. Some of my friends are often in mission and it sounds exciting to me.
Waiting for feedback ;)