A couple of months ago, I requested our readers "tell me about your favorite, interesting Internet tool. An awesome site for nonprofits, a nifty little utility, a Web 2.0 opportunity, a Firefox extension, or whatever." Below, you'll find five brief reviews contributed by five different people ... but please, let's not stop here. Send me a short note sharing something you think others should know about or post a comment below!

My current favorite useful app is The File Splitter.

File Splitter can break large files into manageable pieces, whether you need to save them to diskettes, send them in pieces over email, etc. The program is very small, its interface very easy to use, and is completely free. Once the file is broken into chunks, an executable file is created that, when needed, will sew the component parts back together again, seamlessly.

—Andrew B. in Colorado

Google Checkout is a great tool that I've recently discovered. It will store your credit card and shipping information for you, just as an account with a commercial website would. However, with Google Checkout, you have the advantage of keeping it in just one place, instead of needing memberships with a number of individual sites and trusting each of them with your personal information. There is a large number of websites that accept Google Checkout (see the list here). The biggest drawback for me is the fact that Amazon.com is not on that list.

—Jacob L. in Iowa

Constant Contact is my tool of choice for mass emailing campaigns. The site is very simple to use and provides all the analytic data (who opened my email, when they opened it, and what they clicked on) that I need. Constant Contact is able to leverage their credibility to avoid SPAM filters.

One of the great features of the site is that they provide great video tutorials to help you learn how to use their system. Plus their support staff is great. Though it is not free, the price is very reasonable, and they give a nice nonprofit discount.

—Steve K. of Colorado

I like using Microsoft Excel because it does so many calculations for me. I mean, I just type in the numbers, and it adds them all up! It's like MAGIC! I can even get it to sort things for me....alphabetical order in a snap! WOW! When I'm done creating financial reports, I can even add little clip art pictures to make it less boring. THEN, on top of it all, I can print it off and show it to my friends. They are always so impressed. Thank you, Microsoft Excel!

—One Satisfied User in Montana

I spend a lot of time on the World Wide Web. I’ll often have dozens of pages open and even more sites bookmarked, and, since I work from home, the office, and a laptop, keeping track of where I’ve been can be difficult.

The Google Browser Sync extension for Firefox has made these cross-computer transitions far, far easier to manage. Basically, Google Browser Sync uses Gmail to synchronize your choice of bookmarks, stored passwords, cookies, browsing history, and even open pages. I use it to keep my Bookmark list exactly the same on each of my computers and extend the familiar "Restore Session" feature to work between computers (when I close Firefox on my work computer and later open it at home, all the pages I was using at work open right up).

Google Browser Sync is available free of charge, works with the free browser Firefox (on Mac, Windows, Linux, etc.), and requires a Google account (also free).

—Brian C. in Colorado