There are a few pieces of software, freely available, that I really like. I like them better than some commercial alternatives. For example, Adobe recently came out with version 2 of their Bridge software. Version 1 was useless, but version 2 is much more usable. Still, I find myself going back to the free XnView for browsing images. It launches and runs significantly faster than the Bridge. I find it useful even as a file browser. You can also use it to convert between file formats and make common adjustments to images like rotating, cropping, contrast and levels. An interesting feature is how it deals with a Photoshop file, it allows you to page through the layers. By default it shows the composite version of the visible layers, but you can click through and look at each individually.
Another nice, free program I keep coming back to is Filezilla. It is a ftp client that has a great user interface.
I was recently introduced to XML Notepad 2007. It is built with .NET and has is a fast, simple, well-designed program for editing XML. It makes ftp operations easy. It amazes me the increasing quality of free and open source software.
While not freeware, I like the inexpensive ZuluPad Pro. It does have a free version, ZuluPad, but I feel the pro version for $15 is worth the price. ZuluPad Pro is a great way to keep a hypertext linked set of notes. I find my document often goes beyond what I intend when I started. It's small and fast and easy to use (Can you see a theme here? I guess it from years of being a Mac user since 1986, though I'm on XP now).