Ancestry have just announced that anyone can search the enhanced indexes to the 1910 United States Census (the thirteenth census) for free until 21st February.
They say " The 1910 United States Census is looking better than ever — just like your chances of finding your parents, grandparents or other relatives in it. Enhancements include:
• Clearer, crisper images
• Improved indexes with two new fields: mother's and father's birthplace
• Millions of alternate names to help you with hard-to-find relatives
Search 93 million improved records from all 50 states, Washington, D.C. and Puerto Rico, plus U.S. Military and Naval Forces."
You do need to give your name and email address, but that's all, and then you get immediate access to the summary records, and you can download the page image for free.