While many A-listers find satisfaction in simply hitting the clubs and attending every big-name event on the planet, a select few actually strive to broaden their horizons by venturing outside of their little comfort zone. Jessica Biel is one of those people.

The actress is joining rapper Lupe Fiasco and singer-songwriter Kenna on a journey up Mount Kilimanjaro this January in connection with Summit on Summit, an organization that helps to raise global awareness about the clean-water crisis (1 billion people worldwide currently do not have access to sanitary drinking water).

Biel’s longtime boyfriend Justin Timberlake is rumored to be participating in the hike as well, though it is only a possibility at this point. Last year he even described a similar endeavor that was in the works.

"I've been training four times a week to get my VO2 [oxygen consumption] levels up to expand my lungs," Justin had told GQ at the time. "We'll climb for a week straight, carrying 30 pounds on our backs. It's going to be intense."

You know where a great spot is to pop the question? At the top of a beautiful mountain … we’re just saying *wink.* (E! Online)

Next: Pilot accused of stalking his ex from the air...