Not really. You will have to wait for Android 2.2 Froyo, which is soon coming to the phone, to let you save apps on the SD card. Note, only some apps will allow you to save on the SD card. Angry Birds will install on the SD card, but not Skype.
My suggestion is to remove apps that are not useful for you and those that take up too much space. Some apps have settings that let them cache on the SD card. Turn that on.
Now if the phone is used, was it previously cleared of apps before? Are you downloading apps through your own Google account?
If you paid for apps, don't worry about erasing them. The Android Market will always remember paid apps marked with your login, so they will always be to be downloaded back again for free anytime in the future or on another phone.
I am @guamguy on Twitter.