My computer was quite sluggish today. At first, I blamed it on Gmail - I am on dev cluster, which gets a new version daily, without any testing, so I hit various bugs in it - including the performance bugs - very often. But after I closed Gmail the sluggishness persisted, so I decided to investigate.
Take a look at the following two pictures. This one has CPU utilization at 10%.
And in this one, the CPU utilization has dropped to zero.
The only difference - the little "free smileys" advertizing craplet that has crept into the background. I had a few of them at some point, and the CPU was at constant 50%...