Barack Obama's first name is the anglicized version of Baraka, which means 'blessing' in Kiswahili (aka Swahili), a language spoken by Senator Obama's Kenyan father.
The word "Barack" is shared among several languages. First, it is a word in the (http://en.wikipedia.org/wiki/Semitic_languages) Semitic family of languages. As such it mistakenly has been thought to have the root in Hebrew written as baruch, but since the word Barak in Hebrew exists independently, pronounced as Barak with no twisting of sounds, it is the true word from which any meaning should be taken. A version in Aramaic (berek), a version in Arabic (baraka). (See Strong's Hebrew Bible Dictionary, entries 1288-1294.) It also occurs as a loan word in non-Semitic languages that have been influenced by these Semitic languages, such as Kiswahili (the most widely spoken African language). As often happens, cognate words are similar in pronunciation. What appears in a later-appearing language may sound like something else in the earlier language. And in English we sometimes see words that are pronounced the same and even spelled the same, but that have very different meanings.
Baraka means 'blessing' in Kiswahili and comes from the Arabic spoken by the Omani Arabs that lived and traded along the coast of East Africa. Though it came to Kiswahili from Arabic it no longer has any sectarian connotations and is in common use amongst East Africans of all faiths. It is a common name for boys in Kenya and Tanzania.
Barack or Barak means 'lightning' in Hebrew. The name Barak is also mentioned in the Bible in the book of Judges. Barak was part of the story of the prophetess Deborah.
Baruch (or Baruwk, Baruk, Strong, 1263) and its cognates berek and baraka all mean the same. Strong, 1288, says "barak, baw-rak', a primitive root; to kneel; by implication to bless God (as an act of adoration), and (vice-versa) man (as a benefit)." (See http://www.virtualchristiancenter.com/biblestudytools/kjvstrongs/STRHEB12.htm)
Regardless of how one spells the name, it gives two possible and not contradictory meanings, and one true meaning. One is "a blessing from God," and another is "a blessing from God that the individual may pass on to others as a benefit to them." and the true meaning that cannot be translated any other way is the name Barak which means Lightning.