The BlogThis! button has disappeared from my Toolbar. What happened to it?
Google Toolbar for Firefox - Help Center
Please be assured that we haven't removed the BlogThis! functionality from the Toolbar. Instead, we've added even more functionality. The Google Toolbar's new 'Send to' button offers all the same features that we offered in our 'BlogThis!' button, along with the option to send information through Gmail and SMS (text mssging).

ok. this took some time to find. couldn't find anyone talking about how the current download of Google Toolbar no longer includes BlogThis button. but it sure did not seem to, I couldn't find it anywhere in the options of the toolbar; or on the toolbar site, reading about features.

anyway at home I still have an earlier version of the Google Toolbar. but if I do update it, and find any reason to want 'BlogThis' along with the new SendTo, I can get a BlogThis link (represented by the words, no orange button, which is fine) from Blogger:
Blogger Help - What is BlogThis! ?
BlogThis! <-- drag this link to your browser's Links bar
also it occurs to me that I could move the orange BlogThis button away from the google toolbar (and in fact it is not currently grouped on my toolbars with the google toolbar items) and maybe it would still be there after the download of the new version toolbar. I wonder.

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dlcs notes fr earlier
Google Help - Firefox Toolbar Version 3 see, no BlogThis. ~ new features are int:
Custom Buttons -get a search button by clicking in any site's search field.
Send To -send any website or clipping to a blog or email.
and, Ggl Docs accessible in browser

oh and huh: Send with Gmail
Have you been frustrated because you can’t set Gmail as your default mail client? We’ve solved that problem by adding a feature into Toolbar that automatically opens whenever you click on an email link.
so my below post - the need for those machinations - is obviated. I had thought I had seen some simple way to choose Gmail as default. here it is.
So! I've selected Google Toolbar Options - Browsing - Send with Gmail
when select 'Send Link' under the file menu, though, Gmail does not open. but I bet it will if I click on an email link.