My Air is fairly well loaded now with programs, HOWEVER, using some of the suggestions and 'tricks' found on this site, I still have a huge amount 75% free. And I'm pretty happy over that one.
Some of the suggestions that WORK well.
1 - installed and use consistantly, XSLIMMER, which strips off foreign language support, and legacy codings. That saves anywhere from 1/3 to 1/2 the size of most applications, especially third party ones.
2 - Using the Time Capsule wireless, I have my entire external iTunes collection, pretty large now, 40 Gigs, on the TC and my iTunes just calls them up as needed.
3 - All DATA is stored on a USB external hung onto the TC via the USB out port, that means my Air really only carries the basic programs and all files are wirelessly sent out to the TC or the USB-TC drives.
Essentially, my MBA is a core use machine, with EVERYTHING possible delegated out to other peripherals or other Macs in the home "system" So, when I'm going to leave with the MBA for travel, I move ONTO the system those music or Podcasts that I will use, and while travelling they are put ONTO the MBA as I download or create files or audios. Upon returning home, I just transfer the appropriate directories back to the storage devices and delete them from the MBA.
4 CoolBook for lowering the voltage has resulted in longer battery life and a MUCH quieter machine with lower fan speeds.
5 - smcFanControl is another must have miniaddon program, having the power to make the fans operate according to the schemes I like.
6 - and of course, LabTick to "fix" the bassawkards light control for the keyboard is must.
Given this setup, I actually believe I will NEVER actually use the entire 74 available gigs in the 1.6 standard machine.
And just about ALL these tricks I got from reading this site, thank you everyone.
PS: - and the Invisible Shield gives my MBA the worlds lightest full protection shell, and my CaseLogic reversable sleeve lets me load it up FAST, and travel light and protected.
THANK YOU ALL!