Two of the most popular are kaisho 楷書: the regular block style that looks closest to the printed word, and gyosho 行書, a semi-cursive script slightly more fluid than kaisho, but not fluid to the point of near-illegibility - as is the case with the very free and flowing sosho 草書.
Above are two examples of the same phrase written in the two styles: kaisho on the left and gyosho on the right.
The phrase is, as most shodo phrases are, a four-character phrase (yon-moji-jukugo 四文字熟語). It is pronounced tosho hitori tanoshimu, and simply means "the solitary pleasure of reading."
Read more about Japanese calligraphy.
Yahoo Japan Auction Service
Rough Guide To Japan