No, not really and it is way too early to do that now for 2012.
He died in office.
Franklin Pierce left office in 1857, at the end of his term in office. He was not nominated for reelection in 1856 and was thus not reelected as President to a second term. While his presidency is considered one of the least effective, he did not leave office prematurely.
To the Adams Family, it isn't customary to leave a tip for the waiter.
John Adams gave up the presidency to Thomas Jefferson in March 4, 1801.
Barack Obama was elected in November 2008. He took office in January 2009, at which time George W Bush left office.
Some presidents are elected to two four year terms and leave office at the end of their term in office. Some presidents are elected to one four year term and leave at the end. The other presidents died in office, except Richard Nixon who was forced to resign.
He left the presidency because he died.
Hoover was defeated in his bid for re-election in 1932 due to a bad economy and a clever campaign by his Democrat opponent, Franklin Roosevelt.
He was assassinated
This depends on the religion or denomination of the missionary. In most churches or denominations, it would be more customary to give the missionaries gifts as they leave, not as they return.
The 42nd President of the United States was Bill Clinton. President Clinton was in office from January 20, 1993 to January 20 2001.
A president about to leave office is referred to as a "Lame Duck" president.