It's just converted to .avi because that's one of the things it does along with converting to .flv and .mp4. Youshit only converts to .flv because not everyone has the server power like Google (which has millions of acres of serverland). It is fixed resolution unless it is smaller.
Allright, you got a point there. Still, they could just drop flv in favor of a different kind of streaming format (but not WMV or Real Media please.)
The extension VideoDownloader works too for Firefox. Even then, it's usually just a link conversion for sites and you change a part of the link to save it.
VideoDownloader is basically the same thing: it opens a page on Keepvid (or actually the sister page of Keepvid which is on another server hosted by the guy that made Keepvid and the extension). Very useful for when you need to grab one of those files.
I use a WMP compatible software called Media Player Classic (which looks like an old version of WMP but under the hood is very different and is open source). You just don't know about adding codec support for base players in Windows that use Directshow, and with Directshow I can convert any format that is playable in WMP/Media Player Classic to most of the common formats, including playing FLV files and changing it to DivX/XviD for the GP2X, but I rarely do things like this because I mostly play games on my GP2X.
Classic I've only ever found useful to replace RealMedia Player and Quicktime Players, for the rest, I found it to be pretty buggy with some videos (codecs crashing, etc) and I never really found the colors it displayed to be true to what they should be. It handles subtitles nicely though. Never knew it converted things to DivX/XviD.
Oh, and I was ofcourse talking about the official, new Windows Media Player. It doesn't support Google Video downloaded AVIs because they use the "goog" FourCC, which Windows Media Player doesn't like at all.
VLC is a nice player, but it does not support a lot of the things I want. I'd basically call it a player that has the basic things needed built and good enough for people that don't know what's going on with video/audio/subtitle decoding (like a Mac vs Linux thing) and is a player that requires no dependencies and plays a lot of formats.
I actually find VLC to do exactly the things I want it to. Preview movies that haven't been downloaded completely without it crashing or doing something weird (MPC often crashed on me when I wanted to do the same) and open up all the files I throw at it. Iso files? No problem. Rar files? Easy. Rar files with ISOs in them? It does those too. Makes me not need to have Alcohol or DAEMON Tools opened up. True, it could really benefit with some extra info about the file you're trying to play. For the rest, I feel it supports most features I use regularly. I don't need a playlist or anything like that, since I'd rather use a player such as XMplay to play my music files. Because of that, VLC is fast. Insanely fast. Which is good.
Ontopic: since FLVs are often small files without many frames, you can convert one easilly with FFMpeg using:
ffmpeg -i INFILE.flv -vcodec xvid -acodec mp3 OUTFILE.avi
Shouldn't give you much quality loss. Make sure your ffmpeg build has LAME and XVID enabled though, otherwise that commandline won't work and give you an error.