PSA, this made a nice difference on my phone--
-Instead of upgrading your ROM (I had done this about 20x), just use Titatnium backup to backup all your apps, then do a clean wipe to one of the latest nightlies.
-Uninstall you dialer helpers. I was using DialerOne, great app, but the droid has to keep both it and the Phone app + Storage in RAM.
-use Root Uninstaller to remove Gallery, Email App. They both like to run in the background (even without email configured) and do "stuff" which inevitably pushes your recently used apps out to flash
-Get the Supercharger v6 script, and configure using the guidelines available on google. Tweaks the OOM priorities for certain apps like launcher in a better way than simply (keep launcher in memory).
-uninstall ADWLauncher (if you prefer LauncherPro like me) from CM7. This one may not run in background, don't recall, but it's not needed.
-don't use anything besides the stock messaging app. It's got a smaller footprint than the other messaging apps.
-turn off compcache and just rely on the OOM manager to do it's job. This is letting me get by running at 600-700mhz instead of faster
-install the Deprimed kernel. Has better scheduler, lots of optimizations from a guy who's been custom compiling Linux kernels for 20 years. He knows what he's doing.
-Post back here to report how these steps worked for you!