Time to go 64bit
As a follow-up to yesterday's post let me restate that the next version of SharePoint is set to be 64bit only. This means that if you have the option any new SharePoint 2007 install should be done using the 64bit version otherwise you will not have an easy upgrade path (not saying that upgrading from 2003 to 2007 is easy but hopefully from 2007 to the next version will be). If you do not run 64bit Windows you would basically have to wipe your system completely and redo the installation.
As there are no guarantees as to what Microsoft will be doing in the future in regards to the upgrades I strongly suggest that any new installations be done using the 64bit versions of the OS and SharePoint now.