In Oracle, a UDT can declare member procedures and functions. An example can be seen here:

http://www.adp-gmbh.ch/ora/plsql/oo/member.html

Oracle documentation can be seen here:

http://download.oracle.com/docs/cd/B28359_01/appdev.111/b28371/adobjbas.htm#i477669

Currently, TEE allows for viewing the type specification and body as text, which is good. If this is possible by querying the dictionary views, I think it might also be a good idea to list member functions and procedures explicitly in the schema browser and maybe provide means to edit them explicitly (not the whole type body). But maybe that's not possible...

**UPDATE**: Method declarations are available from SYS.USER_TYPE_METHODS. Method arguments are also in SYS.USER_ARGUMENTS...