I just installed Ubuntu Unity on my desktop PC and it is very lag and annoying! Any ideas?
Unity has known performance problems due to the mutter window manager. For this reason, Unity is switching to compiz next release - Ubuntu 11.04. You are probably better off waiting until then before using it.
Reporting a bug may help the developers. To do this press Alt+F2 and enter:
You can get a similar interface to the Unity dock with applications such as Docky .
You are probably experiencing a isolated problem. Try to report a bug at launchpad.net, and don't forget to offer details like: your hardware, devices, and how did you installed Unity.