There are more than one artists with this name:

1) Geo or Just Geo is a UK based Producer DJ and Music artist. Specialising in Grime music.

Check out the links below for more of Geo's stuff!

https://twitter.com/justgeouk
http://justgeo.co.uk
http://soundcloud.com/justgeo

2) Geo (지오, not to be confused with MBLAQ's G.O) is a Korean singer/songwriter. He is also the CEO of Paran Music. The songs he has released untill now are instrumental (electronica) songs.
source: http://mardi09.wordpress.com/