There is not an Android 2.2 USB to VGA pathway. You cannot use the devices made for PCs.
There is a way to do this using the Mini-HDMI port on the 101. You can connect it to any monitor or projector which has an HDMI interface built-in. The other way is to purchase a powered HDMI to DVI or VGA converter. Note, I emphasize powered and remember it is not cheap. The cheapest which work are ~$100USD.
I have done the first option to great success on a projector which had HDMI connector point. A thing that helps is to deres the powerpoint to a 1024x768 logic. The converter solution does work. but remember the unit is an additional cost and one more thing to carry or go wrong.