I've been using Nicovideo Redirector to watch interesting indie and other gameplay videos on the Japanese Nicovideo site for a while now, but here's a method that works even better.

Just copy the id of a video you would like to watch (e.g. sm8849393 from the URL http://www.nicovideo.jp/watch/sm8849393), then add it to the end of this url: http://www.nicozon.net/player.html?video_id= (e.g. http://www.nicozon.net/player.html?video_id=sm8849393) - in this case a Japanese speedrun of the game Dungeon.

You can then watch the Nicovideo clip in full screen mode without having the need to register or login. Another (non-indie) Ridge Racer Vs. GTA IV game-related example here (thanks to Kenta Cho for this one): http://www.nicozon.net/player.html?video_id=sm8727625

Trailers for upcoming indie games in the extended.

untitled underwater shooter game, by Charlie's Games

Stair Dismount iPhone, by Secret Exit

Sword of Fargoal

Johnny Platform Saves Christmas, by Ishisoft (xnPlay article)

Squid Yes! Not So Octopus Xbox 360 (playable now on XBLIG)

Zero Gear by NimbleBit

Screwball, by Dark Castle Software

Anamaton, by Teknogames

Bytejacker Episode 063: Aaaaa! – A Reckless Disregard for Gravity, and more

Cut and Paste by Turtle Cream (playable now, GameSetWatch write-up)

teaser trailer for Dooder, by Matthew Seely