It took me a while to convert my userscript into a simple extension that is for Safari (version > 5).
I have to check every detail of on Safari document pages ...
Evently, I made it!
Here it is, pubmeder for Safari
pubmeder-v01.safariextz (unzip and drag it to your Safari window)
Also, you can get it from either mirror1 or mirror2. If you know how to submit to Apple's Safari Extensions Gallery, let me know ...
I have put a nice setting page under Safari - Preferences - Extensions

You can either copy&paste the apikey from the email you got when you register or visit http://pubmeder.appspot.com/registration and the extension will extract the info by itself - smart ha
Oh, by the way, I also implant an email processor on pubmeder.appspot.com
to: input@pubmeder.appspotmail.com
subject: containing word pubmeder
body: only containing pmid list
Something like the following will do

The items will be processed and entered into your account / sender's email.
Anyway, enjoy pubmeder and let me know what do you think. There is no extension or add-on capability for IE, right?
Cool! I am excited to try this.
let me know if you have any bug report or feature request :-)