do you ONLY use it for your internet browser?
i have my hand hovering over the 8gb kingston and 2samsung ssd's at the moment
anyway for the ramdrive you can really do what you want, you can store cache of lots of programs, e-mail apps, internet files you can even set things you want to keep to disk aswell but say every 15 mins, or every 2 hours, and you can setup it up to write to disk at a press of a button so you can backup permanently what you like. Its mostly so you don't keep cache the same page to hard disk which will change constantly, and temp files you really don't need to write to hdd just to get deleted when you reboot anyway can just stay in mem and get deleted without the added wear/tear of writes to the ssd.
To be honest I'm not sure how much it helps with longevity, no one knows yet to be honest. Its not really about speed either, its mostly about limiting small writes to the drive.
The ramdisk for readyboost thing, has anyone tested it yet, if you've disabled pagefile windows will still somestimes use a pagefile, mostly because its an ass. But if you have readyboost with pagefile disabled, seeing as its a backup copy of pagefile, does it actually get used, but most importantly, if you enable pagefile but set it to use the ramdisk and only the ramdisk is that the best way forwards.
Ultimately its all down to terrible windows design, some programs crash without pagefile enabled, even if theres more than enough memory for the data to sit in, programmers, and windows just sets some data to not be in memory but to be in pagefile "just in case".
I'm really hating how long windows and other software, hardware to takes to move forwards. Frankly Vista should only ever have been 64bit to force everyone to support 64bit only, get it done and not drag it out. THe 64/32bit driver redundancy is a large reason for how massive a vista install is, look in the driver folders, its insane the amount of old crap they support instead of leaving it on dvd for you to install from if needed, then they install a 32bit driver backup aswell. if Vista had been 64bit only but with the 32bit backup at least most of the industry would be so 64bit ready Windows 7 could be 64bit only with no trouble and do away with all the redundancy.