Connecting more than 10 forums at one database,can i?

[محروم.كوم]

Hi, i have domain such as www.xxxbxxx.com and want to setup a script of forum which will be www.xxxbxxx.com/vb and setup more than forum such vb1 , vb2 , vb3 ,..etc.

all of those forums i want them on the same database ..
For clarification :
www.xxxbxxx.com/vb >>>> For movies,songs,stories,poetry,programs,...,etc.
www.xxxbxxx.com/vb1 >>> For Google,Yahoo,Microsoft,other Internet Companies,..,etc.
www.xxxbxxx.com/vb2 >>> For science,students,Scientific articles,...,etc.

and want member how register in such www.xxxbxxx.com/vb can login any another forums which i mentioned before WITHOUT further registration on each of them!
Can i? __DEFINE_LIKE_SHARE__