RE: #4, the copy on select, Linux does that already, just select, move to the other app, and press the middle mouse button (or buttons one and two simultaneously if you don’t have such a beast), and there you go.

The copy plain text was a wonderful addition to my addon list, thanks!

Regarding the split browser addon, do you know if there is a detach this tab type thing for firefox? I know some browsers, like KDE’s konqueror, has it, so…

Both Diigo and Clipmarks are simpler though for being online (hence less problems with portability/accessibility). What Diigo lacks over Scrapbook is made up by it’s e-mail sending and blog significant features. In addition, Diigo has a feature called Webslides, synchs with delicious and several other social bookmarking sites and has a Diigolet button that works in Safari, Opera and IE. The button though doesn’t synch with other social bookmarking sites as far as I know.

Speaking of Opera, I do think the abilities of the browser warrant the OperaView Firefox extension to be included here. It is an extension which allows the page to quickly be opened into Opera without having to copy the url and paste it into the address bar. (though Opera makes this easy by having paste and go natively)

This cuts down on the above lists since many of the tasks are transferred to Opera which is both lighter and doesn’t require extensions.

1. Copy Plain Text - I think Opera still does this by default which leaves Firefox for the times when you want to copy something which includes formatting.
2. Split Browser - Opera’s a MDI browser so there shouldn’t be any problems doing this.
3. AutoCopy - This is the major reason why I think OperaView should be included. Despite the additional options to turn autcopy on/off, I find autocopying to remain cumbersome. Opera doesn’t have autocopying however it has this thing called copy to note which solves the autocopying problem by copying the text into Opera’s Notes Panel. It isn’t the same as time saving the action however it does give a good overview of the multiple copies before pasting it into some place else or it allows the user to organize it, leave it alone, close the browser, come back and then paste the bunch of snippets.

Autocopying at least for me, is something which I have never found much use for and has been something I used when I remained ignorant of clipboard managers (at least for Windows, haven’t found any clipboard managers for Linux which can save snippets into folders besides Opera)

Note that there are notebook extensions for Firefox like Google Notebooks/Zotero that can substitute for this feature.
4. Signature - Haven’t tried it though it does sound alot like how Opera works with it’s insert note feature.
5. Dictionary Search - Similar to Firefox’s with the exception that it’s pre-installed in Opera. The advantage with Opera is that you get an address bar by pressing F2 which makes it easier to get rid of the search box and the address bar when searching.

I would also include the Speed Dial firefox extension (again, available in Opera) and add Onelook.com (preferred site over Dictionary.com) and Thesaurus.com as an alternative for those who prefer clicking to the main pages rather than typing on a search box. Other optional ones I’d insert would be Critique Checker and Cliche Finder. This one: http://cliche.theinfo.org/