The way I look at it is: An in-house same-domain solution's the slickest and fastest.... but you lose out on any network-effect recommendations.
That said, facebook widgets are ridiculously expensive in terms of domain lookups and requests.
But back to the topic of tweet buttons. Twitter's 3-request button beats the heck out of the Tweetmeme iframe+javascript franken-thing. I just looked on Tweetmeme's site ( http://tweetmeme.com/about/retweet_button ), and even they recommend using the twitter button: "We recommend using the Twitter Tweet Button. You can find more details about it on the Twitter goodies page."
That said, facebook widgets are ridiculously expensive in terms of domain lookups and requests.
But back to the topic of tweet buttons. Twitter's 3-request button beats the heck out of the Tweetmeme iframe+javascript franken-thing. I just looked on Tweetmeme's site ( http://tweetmeme.com/about/retweet_button ), and even they recommend using the twitter button: "We recommend using the Twitter Tweet Button. You can find more details about it on the Twitter goodies page."