RTMPDump is the best, if not the easiest to use. It's CLI only, and is available in the repos, so you can record the streams on the N900. EDIT: I should add that the youtube-dl script works for sites other than YouTube (and does infact make use of RTMPDump), and is easier to use. It doesn't work for all sites, though, so it's less flexible. EDIT2: Maybe one day I will add support for some pR0n sites in cuteTube.