If your work computer doesn’t allow any software installations, you can always grab a USB flash drive and use “green” software, AKA the ones that do not use system registry and don’t leave any files around other than the folder that they reside in. You can find many good examples at http://www.kikizas.net/en/usbapps.html.
Some of the ones that I use as a financial analyst:
PStart (Screens): a program launcher with note-taking ability. Assign a keyboard shortcut for it, and you will have all the commonly used apps at your fingertips.
ArsClip: If you work with Bloomberg terminals, Excel databases, or applications based on IBM Personal Communications, you’ll love the ability to have the most commonly used commands listed by pressing a key or two. It is essentially a clipboard aggregator, but by utilizing permanent items, you can assign a long type-up into 2 keystrokes, even having the program tab or move up/down for you. It can group certain permanent commands together and auto-assign groups for different software. I wouldn’t say that it’s the best thing since sliced bread but it comes close. Oh yea BTW it is frequently updated by the author, and he’s happy to answer your questions on the forum.
Firefox Portable with your favorite Extensions and Themes, even bookmarks and passwords. Need I say more?
I truely believe that by utilizing keyboard shortcuts, one can save up to an hour everyday while working on the computer, plus if you use an egronomic keyboard like I do, it is much more comfortable to keep your hands on the keyboard than using the mouse.