How can I get Little Blocks to work on my Bukkit server?

so, I decided that I wanted the Little Blocks mod on my server, but havn't put any mods on the server (just plugins). I knew that it's designed to be put straight into a .jar file, so I put it in craftbukkit's .jar file. I also installed modloader MP, and, figuring it couldn't hurt (and after trying it without), the regular modloader. I ran the server, tried it, and I get a flash of the little blocks block, but then it went away. How can I solve this? I'm running craftbukkit-1.1-R4.jar.