You can

• Change the resolution of the monitor
• You can change the default text size, but half of the web pages probably override

Items you're already probably familiar with

• Try using Ctrl+0 to restore zoom to normal (Ctrl+- zooms out, Ctrl++ zooms in )
• The problem with the Zoom toolbar buttons (+ and -) builtin to Firefox 4 is that there is no way to zoom directly to normal (100%) nor even tell what zoom level you are at.

If that doesn't work see what you have for Tools > Options > Content > Advanced (see picture, ignore the red circles, it's the font size you might change)

For more control over zooming things see these zoom links

To set the zoom permanently on a per site basis, try the NoSquint

If you are going to switch back and forth between monitors you might try the extension that changes the zoom level (Default FullZoom Level) with a level indicator, which optionally remembers on a per site basis.

My preference is mouse zoom extension zoom text only, and use Image Zoom to zoom an image if needed.

If you want to change the font in the Firefox interface, install this add-on: https://addons.mozilla.org/en-US/firefox/addon/theme-font-size-changer/

Edit: The above add-on looks WAY easier than what I posted. You can refer to this if the above doesn't work for you.

The browser "chrome" (everything around the document) is sized according to your Windows settings, and some styles set in the Firefox software. You can use the Stylish add-on to override and tweak those settings. (You also can use it to tweak styles in web pages.)

Stylish :: Add-ons for Firefox

For example, to increase the font of the menu bar, navigation toolbar, bookmarks toolbar, Find bar and sidebars, you could create this new rule in Stylish:

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);
menubar > menu {font-size:125% !important;}
#navbar, #urlbar, #searchbar {font-size:125% !important;}
#TabsToolbar {font-size:125% !important;}
#PersonalToolbar {font-size:125% !important;}
#FindToolbar {font-size:125% !important}
#sidebar-header, #bookmarksPanel, #history-panel {font-size:125% !important;}

It take some practice to write style rules, but you can get more help here to pick up on what I've missed.

So how to do it? Once you install Stylish, you should see an "S" icon in a box on your Add-ons bar, with a little drop-marker triangle next to it.

1. Copy the above style rule to the clipboard.
2. Click the Stylish icon and choose Write new Style.
3. Paste the rule text and click Preview. The effect should be immediate and fairly dramatic. If 125% doesn't suit you, try other values and Preview again.
4. Name your new Stylish rule and Save.

Any luck?

---

To edit your rule after saving, you normally have to go the Add-ons page and click Options. This is inconvenient for styling some bars that do not appear on that page. You can manage your Stylish rules in a pop-up instead by changing a preference.

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the filter box, type or paste stylish and pause while the list is filtered

(3) Double-click extensions.stylish.manageView and change its value to 1 (the default is 0).

You're done. Now when you choose Manage Styles from the Stylish icon, you'll get a pop-up in your current tab rather than changing to the Add-ons page.

Thanks all for the answers. I've downloaded Xircal's add-on idea and will go play with that. Thanks again, Pat