Since 2012 is still on extension and is the only year that can still be electronically filed that is the default.
Regardless of the software you use a 2011 return has to be printed, signed and mailed.
You can access prior years of TaxAct at http://www.taxact.com/products/all_previous.asp
"You can complete and print your return.
One-time Data Archive Service fee applies - $13.95."
The 1099G will be able to be entered in the program and included as income on your 2011 tax return.
Sorry to say that there are fees to do the 2011 return from many companies either for the federal or state return.
For example at http://www.freetaxusa.com/file_2011_income_tax_return.jsp it says Free 2011 Federal Tax Return Preparation and Add a State Return for Only $9.95
No matter how or where the 2011 is done it has to be printed and a hard copy sent in the mail.
Please ask if you need more information.