Here's an instructional video on how to make flipnote compilations.
Flipnote Studios is a free DSiWare app, it supports 2 layers, each with one colour from a vast choice of 3. It has one screen resolution 256x192 pixels. It has 8 speeds, ranging from 0.5 to 30 fps. It can import photos from your DSi's photo album, single coloured on 1 layer.
It has a very limited range of tools, the only transform tool available is a zoom tool which can double of half a layers size, that's it. You can choose to upload your flipnotes 'unlocked' so other users can edit them. A great idea, there are some great collaborations.
It supports sound too, 3 sound banks (2 seconds long) and a 'soundtrack' soundbank which can record 1 minute of uninterrupted sound. All in all a flipnote can fill about 1 megabyte. Sounds crap right? I thought so too, but I figured I'd download it and try it. I learnt how to use the program in a matter of minutes and I was instantly hooked. I have never exploited flipnote studio to it's limits, but some people do. There are some truly amazing flipnotes out there and there is a lot of talent.
There is however a lot of crap. We all know the story from youtube. A single picture with a song playing in the background, countless copied flipnotes (a previously unlocked flipnote, that is reposted by another user who makes no changes at all).
The best thing about flipnote studio is by far the community, which runs perfectly well on a DSi, comments can be written using your DSi touchscreen. They appear instantly on the comments screen. There can be some great chats on flipnote hatena. The community can also be accessed via a PC or on the DSi's browser. Comments are typed in here though, the update isn't as fluid, and flipnotes don't sync well on a PC. In the DSi browser there is no sound and the animations are slower. The community is definitely best from the DSI app.
Writing comments on a PC can be an ordeal, as there is strict censor. The censor is unable to read a handwritten comment, but be warned, profanity will be detected and removed. There are lots of idiots in the flipnote community who like nothing better than to report inappropriate comments or flipnotes so that they are removed, and the creator of the removed content can be warned or even banned from using the service all together.