Connected Internet has a list of four WordPress plugins you should leave alone, that is, not install. While I don’€™t feel like adding to the list at this time, I do agree on the Gravatar part:
These plugins don’€™t seem to be resource drains because they are constantly pinging the server to see if new images are available. Use with caution
For those of you that don’€™t know it, Gravatar supplies the small images connected to your registered user here on The Blog Herald. Regular readers also know that it has been broken more than not during the past months. Gravatar are having serious problems and personally I don’€™t think you should use them. Then again, I’€™m no fan of hosted third-party solutions that aren’€™t really necessary in the first place, so’€¦
Read the rest of the list over at Connected Internet.