"I want to take advantage of mobile commerce and allow visitors to purchase products or make donations through my mobile site."
Very easy to do!
The MoFuse platform supports both PayPal and Google Checkout. Note that to use either option, you will first have to have created a PayPal or Google Checkout account with the respective service.
Then, it's as simple as creating a new PayPal or Google Checkout element in the 'Add Elements' page, and adding that new element to your Active Site Layout in the 'Site Layout' page.