Open Source Software

Some of these I've used. Some I've just seen recommended elsewhere:

Security

anti-virus AVG Anti-Virus 7.5 (grisoft.com) | Avast Anti-Virus | ClamWin GPL Anti-Virus
anti-malware a-squared (emsisoft.com) | ad-aware
privacy Vidalia/Tor Package | Torbutton Firefox Extension (for use with Tor)
encryption GPG
password mushpup disposable passwords

KOSS (Klenwell Recommendations)

os ubuntu linux
browser Firefox
email Gmail | Thunderbird
code editor Komodo Edit | HTML-Kit
graphics GIMP (for windows) gimpshop (photoshop UI emulator)
zip 7-Zip
ftp Filezilla
db designer DB Designer 4

Others

js editor Aptana

Free or Open Services

remote image hosting http://imageshack.us/ http://www.onedump.com/ http://www.bayimg.com/

Reference

Why Popular Anti-Virus Apps 'Don't Work' (slashdot.org)

CategoryCategory
Valid XHTML 1.0 Transitional • Valid CSS • WikkaWiki