Bukkit

Automatically create backup folders for worlds

Ascii Bukkit Menu

Hypnos is plugin about sleeping.

Stop breaking and placing of blocks if a player doesn't have a permission

Don't let your players enter a world (forever or temporarly) if they die in it.

BorderVisualizer

Create FarmWorlds which automatically regenerates after specified days

Player created dungeons

Nethrar

Make roads, bridges and tunnels as you walk with custom road templates.

Change those mob spawner types!

SketchMap allows you to put Visual images on maps and or display them using item frames

SWatchdog is ultralightweight blocklogger, similar to bigbrother. Also allows to rollback griefs in specified area

Make regions that players can buy/sell

Edit world voxels

Periodically delete unused regions and chunks.

Manage worlds

Makes snow more "real" and configurable.

No Explosions

Design your dream house on a bukkit server but don't have the resources for it yet, design it now and give resources later!