Ask HN: Best way to raise money for a small charity trip?

My little sister is in high school, and recently spent a week in Haiti on a medical mission with a group of doctors/residents (including my mom, who's a pediatric radiologist).

She's trying to brainstorm ways to raise money for the group's next trip. I believe the trips are semi-annual, and they need money for all sorts of things: medical supplies, food (both for the doctors and the patients, many of whom have to walk a full day to get to the clinic), transportation, lodging, etc.

I guess she could do a bake sale or something, but I was wondering if you guys knew of any interesting ways she could cast a wider net than just her high school community.

She has some pretty amazing photographs from the trip, so I was thinking that something as simple as a posterous page with a pledgie link would work; but I'm not very familiar with online charity strategies.

I'd be incredibly grateful for any cool ideas!