the best fix i have found for this issue, and it has worked wonders for many people (so much so that some roms include it stock), is from samsonite801:
If you use ADW or LauncherPro and if after using your browser, email or any other apps for awhile, then if you press the 'HOME' button, if it takes forever to redraw your home screen, and you are sick of that HORRIBLE LAG, then try this: In a terminal, type su and enter. Then type echo ro.HOME_APP_ADJ=1 >> /data/local.prop and enter. Then reboot. Now evaluate whether or not this fixes your lag. If you want to undo what this command does, simply remove that toggle from: /data/local.prop
To remove the toggle: In Root Explorer, go to /data/, tap Mount R/W at the top, then long-press on local.prop and Open in Text Editor, then delete the line: ro.HOME_APP_ADJ=1.
unfortunately, this is for root users only. i'm unaware of anything for stock people, except for monkeying with the launcher settings.