First, it is possible to find out how much user memory is available on a given machine, and to find out if there’s a lot of swapping going on:
set UsrMem to ((do shell script "/usr/sbin/sysctl -n hw.usermem") / 1048576) as integer
set SwapUse to word 6 of (do shell script "/usr/sbin/sysctl -n vm.swapusage")
display dialog "The available user memory is " & UsrMem & "MB," & return & "and the swap space now in use is " & SwapUse & "B"
Something else of some interest is how long you’ve been running since the last start or restart. This requires an osax otherwise very useful in timing scripts called GetMilliSec 1.0.1 to be found in osaxen.com (part of MacScripter). It can be downloaded from this link and put in your ~/Library/ScriptingAdditions/ folder
The script is a slight modification of one that appeared in the forums (but I can’t recall who it was, unfortunately). It goes like this (Using Kai’s method of getting an icon):
set theIcon to ((path to application "iCal" as Unicode text) & "Contents:Resources:App.icns") as alias
set t to (GetMilliSec) / 1000.0
set hh to t div 3600.0
set t to t - hh * 3600.0
set mm to t div 60.0
set t to t - mm * 60.0
set ss to t as integer
display dialog "It has been " & hh & " Hrs, " & mm & " Min, " & ss & " Secs" & return & "since last system start or restart on" & return & (current date) - (GetMilliSec) / 1000.0 with icon theIcon