Forgive me for "selling" YinI, but hey...
The Year in Industry have recently introduced a new scheme they call the YinI Combo, which will be available for applicants in the next cycle (i.e. taking a gap year 2008-9). It combines a placement and travel option.
YinI have joined up with four companies (BUNAC, Raleigh International, Projects Abroad and Coral Cay) to provide you with the opportunity go travelling and get the benefit of a year working in industry. You also get a discount on your travel placement. You work from August/September through to May if you're doing BUNAC or June if you're doing the others.
Basically, when you sign up for YinI you'll have to tick a box or something saying that you're interested in doing the combo. If you get a placement (bear in mind that it's not guaranteed that you will), your manager person has to sign off that it's OK for you to not work the full year and then I assume you're sorted.
I'm doing YinI this year, and have already got my travel plans sorted for August next year, so you don't HAVE to do it through the combo scheme. It makes sense, though, seeing as you get the discount (it's something like 10 or 15%, which is really good) and you know you've got the support of you company.