F-Secure - Has handheld security info, products and news including a file encryption application and anti-virus products for Palm, Pocket PC's, and Symbian.

VirusScan Mobile - VirusScan Mobile by McAfee.com scans and cleans files, e-mails, Internet downloads, text messages, and attachments for smartphones and Pocket PCs.

Symantec AntiVirus - Symantec AntiVirus for the Palm OS and Pocket PC provides virus defense for your handheld device . Installs and synchronizes easily with your PC.

WMT security downloads - This WindowsMobileToday page has security downloads for Pocket PC and P/PC users.

PalmSpot Security downloads - This page has many security downloads for Palm users.

PDA Defense - PDA Defense is a PDA security software solution for Palm, Pocket PC and Blackberry devices. This Palm security software solution is available in Standard and Professional versions.

ITSMed PDA Security Guide -  This guide discusses PDA data encryption and protection, securing data on a multi-user PDA, PDA password protection, anti-virus, and the future of PDA security.

CrypBox for Palm OS -  CrypBox stores all your confidential information like passwords, account numbers, logins, PIN's and URL's. It uses the BlowFish encryption algorithm to keep your data safe. Allows you to only need one password.

Pointsec - Has an image password system and total system encryption products for Palm and Pocket PC products.

PC-cillin for Wireless - Offers on-demand antivirus protection for Palm and Pocket PCs.

Firepad - Has live video surveillance software for Palm OS handhelds, including Treo and Tungsten.

Splashdata - Security and productivity software for Palm, Treo, Pocket PC, and Smartphones.