It seems like many people around the world are complaining that Google's properties, including Google Search and Gmail are both either down for them or incredibly slow. For me, it is working well, but I had people call, email and IM me about the issue.
Plus, if you look at a Twitter Search for google, you will see many are saying it is slow or down, at the moment.
We do have a few threads in the Google forums, here is one from the Google Web Search Help discussion forums.
I assume there are some server or network issues with the major backbones causing the slowness or downtime. I also assume things will return to normal soon.
We're aware of a problem with Google Mail affecting a small subset of users. The affected users are unable to access Google Mail. We will provide an update by May 14, 2009 11:23:00 AM UTC-4 detailing when we expect to resolve the problem. Please note that this resolution time is an estimate and may change.
*This may also be affecting other services
Forum discussion at Google Web Search Help.