Hey, assuming you upgraded to 2.2. If you go into Settings-->Applications-->Mange Applications. Then hit the Menu Button and select "Sort By Size"
Then try to move the biggest ones you can to SD. (select the application then you will see a Move To SD button).
Not all apps can be moved, only ones which the app developer allows. Also, do not move widgets to SD because then they will not work.
However, there is another method which requires root. There was a thread about it here- Acer Liquid E internal storage