There are many useful (and free) sites out on the web. Here is a list of some that I find particularly useful.
Bubbl is a concept mapping tool. It is great for brainstorming and mapping events.
Jing is a screen capture tool. You download it and it allows you to clip any part of anything that is displayed on a web page or any other type of document.
Timetoast is a timeline creator. This is especially useful for event planners. You can create a timeline for anything, past, present or future. You can even add images. You simply fill in the details, choose a date and Voila.
Wordle is a word cloud creator. You can cut and paste any amount of copy and it will make a word cloud. The more often a word is used, the larger it will appear in the cloud. You can print them out and save them. (The illustration for this post was made with Wordle.)
Tineye is a reverse image lookup. If you have a photo and you want to know its source, to perhaps ask permission to use the image, you can just upload the image and (at least for me) you get the source about 80% of the time.
Showmystreet does just that. Start typing in any address and you will see the street.
Tag Galaxyis a fun site, where you can enter a tag and it will create a galaxy with all of the photos on Flickr http://www.flickr.com that use that tag.
What Do You Love is a Google offering. You type what you want to know more about into the box and wait. You will be amazed at the different sources it searches. To test it, type "pizza" into the text box.
Business Card Maker does just that. It creates a business card for you. They have an assortment of templates.
Find Sounds will find sounds that you can use on any device.
Lovely Charts allows you to create professional looking diagrams, flowcharts, site maps, organization charts, etc.
PDF to Word will convert PDF files to Word documents. I have only found issues when the PDF has graphics on it.