What treaties has the president signed with other countries?

Answer 1

As of May 18, 2012, there were 34 treaties pending ratification before the Senate; most of these were submitted by presidents dating back to Truman. Eleven of those pending ratification were submitted by President Obama, listed here from the State Department's Treaties Pending list

1. Annex VI on Liability Arising From Environmental Emergencies to the Protocol on Environmental Protection to the Antarctic Treaty (Annex VI), adopted on June 14, 2005 (Treaty Doc. 111-2); submitted to Senate April 2, 2009.
2. Convention between the Government of the United States of America and the Government of the Republic of Hungary for the Avoidance of Double Taxation and the Prevention of Fiscal Evasion with Respect to Taxes on Income, signed at Budapest February 4, 2010, with related exchange of notes (Treaty Doc.: 111-7); submitted to Senate November 15, 2010.
3. Protocol Amending the Convention between the Government of the United States of America and the Government of the Grand Duchy of Luxembourg for the Avoidance of Double Taxation and the Prevention of Fiscal Evasion with Respect to Taxes on Income and Capital, signed at Luxembourg May 20, 2009, with related exchange of notes (Treaty Doc.: 111-8); submitted to Senate November 15, 2010.
4. Protocol Amending the Convention between the United States of America and the Swiss Confederation for the Avoidance of Double Taxation with Respect to Taxes on Income, signed at Washington on October 2, 1996, signed at Washington September 23, 2009, with related exchanges of notes (Treaty Doc.: 112-1); submitted to Senate January 26, 2011.
5. Protocols 1, 2, and 3 to the South Pacific Nuclear Free Zone Treaty, done at Suva August 8, 1986, and signed on behalf of the United States on March 25, 1996 (Treaty Doc.: 112-2); submitted to Senate May 2, 2011.
6. Protocols I and II to the African Nuclear-Weapon-Free Zone Treaty, done at Cairo April 11, 1996 and signed that day on behalf of the United States (Treaty Doc.: 112-3); submitted to Senate May 2, 2011.
7. Agreement on Port State Measures to Prevent, Deter and Eliminate Illegal, Unreported and Unregulated Fishing, done in Rome November 22, 2009 and signed that day on behalf of the United States (Treaty Doc.: 112-4); submitted to Senate November 14, 2011.
8. Protocol Amending the Convention on Mutual Administrative Assistance in Tax Matters, done at Paris May 27, 2010 and signed that day on behalf of the United States (Treaty Doc.: 112-5); submitted to Senate May 17, 2012.
9. Convention on the Law Applicable to Certain Rights in Respect of Securities held with an Intermediary, done at The Hague July 5, 2006 and signed that day on behalf of the United States (Treaty Doc.: 112-6); submitted to Senate May 17, 2012.
10. Convention on the Rights of Persons with Disabilities, adopted by the United Nations General Assembly on December 13, 2006 and signed on behalf of the United States on June 30, 2009 (Treaty Doc.: 112-7); submitted to Senate May 17, 2012.
11. Convention between the Government of the United States of America and the Government of the Republic of Chile for the Avoidance of Double Taxation and the Prevention of Fiscal Evasion with Respect to Taxes on Income and Capital, with Protocol, signed at Washington February 4, 2010, as corrected by exchanges of notes effected February 25, 2011 and February 10 and 21, 2012, with related agreement effected by exchange of notes on February 4, 2010 (Treaty Doc.: 112-8); submitted to Senate May 17, 2012.

In addition, President Obama signed a new START Treaty with Russia in 2010, and the Senate ratified it in December of that year.

I have been unable to find a definitive list of treaties at the State Department site, the White House site, or in any other venue.