Secunia Personal Software Inspector is very helpful. It detects all the software you have installed and runs a scan once a week to determine if any of it is out of date and gives you easy links to the updated versions. You sound like you're doing quite well, though I would add Quicktime (comes wirh iTunes) to the flash and java list, but even if you're doing a great job Secunia PSI can be a nice reminder and/or provides a visible confirmation that you're all patched up.

https://secunia.com/vulnerability_scanning/personal/