For your Firefox:
No matter how much I love Firefox, occasionally I need Internet Explorer – because there are stupid sites that don’t work properly with FF, or when I’m testing that my site does work in IE. But I might never need to open IE again, now I have this little FF extension. Once installed, all you have to do is right-click on the page you’re in and select ‘view in IE tab’. (And I just noticed that if you right-click on a hyperlink, it gives you the option to open the link in IE too.)
The other FF extension I currently swear by is Adblock (I owe the friend who pointed me to this one several large drinks). Get this and you will never have to look at all those annoying adverts on websites ever again (graphics, anyway; it won’t block text advertising).
For your WordPress:
Live Comment Preview. I’m not sure it’s particularly useful but I quite like it.
Update: Unfortunately, my lovely new FF extension is showing that the preview plugin doesn’t work in IE. Oops.
Oh, and it seems that something odd happens to the comment text box in IE when you start to type in it (it suddenly gets wider). I’ve never spotted that before and I have no idea what’s going on there. Time for some CSS investigation, I think. (fixed) Well, at least it shows the new extension is already earning its keep.
Last update, hopefully: Ho hum. Looks like live preview does work in IE… It just doesn’t work in the IE-FF extension. Ah well, nobody’s perfect. At least the extension does work perfectly for downloading PDFs from JSTOR, which has been giving me all sorts of trouble in Firefox.