I recently stumbled across a trick (er, I mean, Feature!) in many MS products that lets you resize the font size - and in some cases, zoom level.  This works in IE, Word, Excel, Visio, and probably many other apps I haven't tried yet.  I'm not sure what the minimum version is of the apps or OS that this works on, but give it a try:

Simply hold the Ctrl key and use the scroll wheel on your mouse (assuming you have such a mouse).  In IE, the font size changes (where the page allows you to; some text won't resize if the size is hard-coded);  in Excel and Word, the zoom level changes.

Many/most of you may already have found this.  But after showing this to a few people who'd never heard of it, I wondered how many others haven't found this handy feature.

Let me know if this doesn't work for you, and if not, what version(s) of the OS and apps you're trying it on.  It may only be XP and Office 2003 products, but I'd hope it works for some previous versions too.