Spybot 2.0 will be friendlier to your resources
Structured into multiple apps for multiple functions (properly integrated so you won't notice) - only those that you currently need will be in memory. For oxample, the "tools" available in advanced mode are not really required to be loaded while scanning, so they're in a sped-up version of RunAlyzer integrated into the package now.
Right now the pure 2.0 scanner uses about half as much memory and a tenth of the number of User objects and GDI objects (the "classical" "resource" items that matter on 98) compared to the 1.6 SpybotSD.exe.
These are not final numbers - the user interface is still missing a few elements, but it's a direction of hope