The is also a SQLServer function called COLUMNPROPERTY that you can use to find Identity colums.  Try the following :

Select O.name as [Table],

       C.name as [Column],

       T.name as [Type]

from sysobjects O

join syscolumns C on (C.id=O.id)

join systypes T   on (T.xtype=C.xtype)

where COLUMNPROPERTY(O.id, C.name, 'IsIdentity')=1

and O.type = 'U'