I have used the spell check icon in the Firebox Google toolbar to check spelling in Blogger post editor and found it superior compared with could be done with the Blogger built-in spell check in Blogger's post editor, especially before Blogger was replaced with Blogger Beta, then became New Blogger of just plain Blogger (just why don't Blogger introduce versions so we don't have to refer to old classic Blogger and New Blogger as even sometimes calling a blog using the old classic Blogger template in New Blogger is different from the really old version of Blogger as with that, you can have labels, which the really old version of Blogger don't have)
Unfortunately, that don't work anymore with FireFox 2.o anymore and you cannot get FireFox 1.5 anymore. So I have to resort to the Blogger built-in spell check which is not my preferred choice. Now even that doesn’t work anymore. I have tested that with 6 browsers - Internet Explorer, FireFox, Opera, Flock, Netscape Navigator and Avant.
I have resorted to a more tedious Workaround for broken Blogger spell check (click BACK button to get back to this page).
Spell check with Google toolbar in Internet ExplorerSince the Blogger built-in spell check is broken, one day I tried doing spell check with the Internet Explorer Google tool bar by clicking on the spell check icon: (before you start spell check, you will see the word "Check". What you see now is "Stop" which will revert you post editor window to normal mode).
You can see the misspelled word in red, the corrected misspelled word in green, and when you click on a highlighted misspelled word (red in color), you will get a drop-down menu with suggestion of various possible correct spelling, one option to edit there and then, one more to "Ignore all", and this useful option - "Add to dictionary". This will be particularly useful if you frequently use words not in their dictionary, especially if you happen to be in a multilingual country and frequently use non-English words.