Language and Travel Guide to Ukraine
Chapter 2, page 14, Visa Categories. On July 1, 2005, Ukraine decreed that Americans returning within six months after a first visit didn't have to obtain a new visa so long as their repeat visit was shorter than 90 days. (This made it easier for business people and other frequent travelers to Ukraine.)
HOWEVER, on August 18, 2005 President Viktor Yushchenko announced that NO VISAS are required for U.S. citizens if their stay in Ukraine is for 90 days or less.
Chapter 4, page 51, Declaration of Personal Items. Regulations about declaring items you're carrying in have been relaxed. There are no longer two corridors, a "red line" and a "green line," which separate travelers according to the nature and quantity of what's in their luggage or carry-on. This is already in operation at Borispil Airport and should be in effect soon at all other points of entry.