Mississippi
South Australia
There is no Australian state which shares a border with all other states. No state except for Victoria shares a land border with Tasmania. South Australia shares a border with all mainland states and the Northern Territory.
Arizona shares its Southern border with Sonora and Baja Califoria, Mexico. To the North Utah shares its southern border with Arizona, and Arizona's western border is marked by the Colorado River to form a border with California and Nevada. The western border of New Mexico is the eastern border of Arizona and Colorado and Arizona touch each other at the Four Corners Monument.
Kentucky and Colorado.
sikkim maybe?
Canada. Canada shares a border with:MaineNew HampshireVermontNew YorkPennsylvaniaOhioMichiganMinnesotaNorth DakotaMontanaIdahoWashingtonAlaskaRead more: http://wiki.answers.com/What_states_share_borders_with_Canada#ixzz1IgDfSa4F
Tennessee shares borders with 8 other states: Alabama, Arkansas, Georgia, Kentucky, Mississippi, Missouri, North Carolina, and Virginia.
Alaska and Hawaii do not share a border with any other US states. Alaska shares a border with the Yukon Territory of Canada.
Both the US state and the country border each other.
Tennessee and Missouri both border 8 states.
Missouri and Tennessee are the only states to border eight others.