The Auto-Reconnector Mod is a Minecraft modification that allows you to automatically reconnect to a server.
This mod is very useful for example when you try connect to a full server: Simply connect once to it and the mod will try to reconnect you as long as you aren't connected successfully. Once you are connected though, you will hear a sound, telling you that you are now ready to play.
Here is a little screenshot of how the reconnecting looks ingame:
Note: I cannot guarantee you that this mod will be allowed on every server. Some servers might ban you when you try to connect to often. USE UNDER OWN RISK!