Apps2SD card is a function that will come with Android 2.2. Your Droid X should be getting Android 2.2 shortly, hopefully within the month. In the meantime, if your phone is getting slow, go to settings, Sd card and phone storage, and take a look at the internal phone storage and internal SD card storage as well.
If there are less than 10-20MB of data left on them, go to settings, applications, manage applications, and remove some apps that you can do without for right now (preferably the ones that are big and useless. You may also want to see if the location where you are saving movies and pictures is almost full, as that may be slowing your phone down as well.
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