I admit I'm an IPhone app junky. I surf iTunes daily for my next fix. I gave the new Cisco SIO IPhone app a spin today. SIO stands for "Security Information On-the-Go" If you are a security professional or someone who keeps up with latest alerts this is an app you would want to consider. As for me i like the security blog and Cisco field notices of the app.
Cisco SIO To Go iPhone Features
Powered by the Cisco Security IntelliShield Alert Manager Service, the Cisco SIO To Go iPhone application informs, protects and enables users to respond in real time to alerts and threats to the network. The 
application delivers early warning intelligence, threat vulnerability and proven Cisco mitigation solutions to users' iPhones as they occur. It also provides unique IP and URL address e-mail and Web reputation look-up powered by the Cisco IronPort® SenderBase Security Network and the Cisco SIO.
Alerts delivered include:
Cisco Product Security Incident Response Team (PSIRT) Alerts
Cisco Intrusion Prevention Systems (IPS) Signatures
Cisco Applied Mitigation Bulletins
Cisco Threat Outbreak Alerts
And many others
Links to the following Cisco security news and information:
Cisco Security Blog
Cisco Cyber Risk Report
Cisco Press Releases
Cisco Security Twitter Feed
Cisco Security Podcasts