Leigh McClelland, AST in MFL at Comberton Village College has written a brilliant guide on getting to grips with the free movie editing software Microsoft MovieMaker which her department make great use of when putting together short clips of foreign language performances in the classroom.
Leigh spoke about the potential of the program for language teachers at last year's Isle of Wight Conference and I've included the audio of her talk That's Edutainment! here which covers the process of capturing video, editing clips together and adding bells and whistles such as transitions and sound effects. Leigh also offers great advice on the type of camera and leads you need to get started as well as many other great film-making tips she's learnt along the way.
For anyone interested in celebrating pupils' work by filming it in the classroom, I would certainly recommend spending the time reading Leigh's guide and listening to her talking about her experiences as you are bound to learn a great deal in a short period of time and have fun too.
Once you've become a proficient film-maker, you may decide you'd like to publish the results in which case I would suggest you use the free site Blip.tv which can host your clips and provide you with an embed code for your blog or wiki so your pupils can watch their lovely creations at home. Make sure you get written permission from the parents of anyone appearing though and don't publish your pupils' full names underneath.