I have not been able to trace a consistent cause, but a few times a day my laptop will hang for up to about a minute. I can still move the cursor which displays as the wait icon for whatever application I was last in, but cannot carry out any other actions.
Unfortunately I can't Ctrl+Alt+Del to bring up a task manager and I just have to wait.
I can't pin it down to a particular application either, but generally I have either office apps, a browser or other tools open.
I'm tempted to think it may be network timeout on something, as I can't think of anything else which would delay for that long with such a significant impact, but as I'm more a Unix person I thought it would be worth asking here.