From CyberWurx Customer Wiki

[edit] Disclaimer

It is HIGHLY recommended that only experienced minecraft server admins proceed!

This is a quote from the bukkit website (RE: 1.5_02 bukkit build)

We have completed the update to Minecraft 1.5_02 (and have had it done for a while now) 
and are working out a few issues before we promote a recommended build. A TEST ONLY build 
is available but we highly recommend that you wait until we promote a Recommended Build 
before putting it on your production server.

You can find the latest test build on ci.bukkit.org. Please note, though, that if you don't 
already know how to get it, you probably shouldn't be using it. Only Recommended Builds
have gone through extensive testing. Anything else could result in unforeseen problems like
Bukkit eating your cake or your world. You have been warned.

[edit] Enable LATEST snapshot build

To enable the latest snapshot build ( http://ci.bukkit.org/job/dev-CraftBukkit/lastSuccessfulBuild/ ) login to the gamepanel and modify the following option in the server configuration.

bukkit

Currently bukkit is set to 0 (disabled) or 1 (enabled). Set this to 2 to enable the developer build of bukkit.

[edit] Disable Snapshot Build

To disable the snapshot build, simply stop your server and set bukkit to 1 (enabled recommended build) or 0 (disabled). Start your server to apply changes.