OpenWengo Code Camp
"OpenWengo Code Camp is a friendly, challenging and mind-stimulating contest aimed at pushing open source software projects forward.
Students apply for proposed software development subjects for which they have a particular interest in. These subject proposals describe ways to bring enhancements to existing or new FOSS projects, generally by writing source code.
If their application is accepted, they get the chance to be mentored by open source software contributors to work during 2 months on the subject for which they applied. At the end of summer, mentors give their appreciation: if goals were successfully reached, students get 3500 euros of cash.
Mentors get 500 euros of cash if they played their role which consist mainly in helping students to complete their work successfully and evaluating their work at intermediate and final stages."
Sounds pretty reasonable to me, and the cash is not bad either :-)