⇒ Opera

for a while (18-24 months) I used Opera exclusively...then Firefox upgraded its tab-switching abilities and I discovered the Cmd + 1, 2, 3... quick-switch shortcut and never looked back. Not that Opera's a bad browser, mind you (its really awesome!) but without the ability to quickly switch between tabs, well there's no going back, just yet...Anyhoo, here are a few shortcuts to speed up the Opera experience:
Keyboard shortcuts
list of features
Mouse gestures. Good idea, but they haven't really caught on with me yet.

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⇒ SEO

SEO Stylesheet for Safari, Firefox, Opera, and IE | Disable Styles and Javascript in Safari with Keyboard Shortcuts - How To | Firefox SEO add-ons | SEO for Firefox | Google preview

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⇒ useful firefox plug-ins

10 good plug-ins here: Sarah's Top Ten Firefox Plug-ins and Extensions and why they're good. Unfortunately, written before Firefox 3.0 launched and thus many of these plug-ins are 2.0 oriented.

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