You should always know where a link takes you before clicking on it. Services like TinyURL.com make that difficult. LongURL Mobile Expander uses the LongURL.org web services to let you know where shortened links *really* go.

Source
https://addons.mozilla.org/en-US/firefox/addon/longurl-mobile-expander/

Rootkit scanner is scanning tool to ensure you for about 99.9%* you're clean of nasty tools. This tool scans for rootkits, backdoors and local exploits by running tests like:
- MD5 hash compare
- Look for default files used by rootkits
- Wrong file permissions for binaries
- Look for suspected strings in LKM and KLD modules
- Look for hidden files
- Optional scan within plaintext and binary files

Download
http://sourceforge.net/projects/rkhunter/