Other

• PDF-Xchange Viewer - Need to comment and annotate a PDF document?  Adobe Reader can do it but it's a 30+ MB download, and makes you download Adobe Download Manager.  Foxit Reader's free version adds a red stamp to the top of your document.  PDF-Xchange viewer is a free download that doesn't install extra crap and doesn't mark up your document.

Web

• Yuarel - URL shortening sites are a dime a dozen, but this one actually lets you "masquerade" the URL, so that the original URL is not displayed in the browser's URL box.  Instead, what's displayed is the http://yuarel.com/ URL you've created. 

E-mail

• Whoreadme.com - A free service that lets you know when someone has opened the e-mail you sent them.  You can send the e-mail from their website or from Outlook or whatever other e-mail program you use.  Simply add 'whoreadme.com' to the end of the recipient's email address.  Caveats: it uses an image for tracking, so programs like Outlook, which block images by default, might thwart its normal operation; make sure you use the reply-to e-mail address when signing-up for the service.

Web

• Ipadpeek.com - Want to see what your site looks like on the iPad?  Here's the site to do it.
• Wakoopa - create a free profile and track all the software you use: what you use most, what you use least, and get recommendations for other software based on what you currently use.  It tracks the websites you visit as well, which makes sense since many websites are more like applications these days (Facebook for example).  I went over their privacy policy and they seem like decent folk who aren't out to collect your data to misuse (sell) later.  My own profile is here.