Can MOSS integrate and get user profiles from multiple Active Directory and/or LDAP stores?
I have seen from Integrating Microsoft SharePoint Server With Oracle Virtual Directory that there may be intermediary products that can help with this.
It looks like Rohati has a solution as well, but is the out of the box without third party products?
Cannot answer for non-AD LDAPs but with with multiple forests where you have a trust, one-way will work, it is no big problem. You need to do two things, add the people to the people picker, http://technet.microsoft.com/en-us/library/cc262051.aspx, and then run a command to import the user profile information, link on above link. Besure to run the command also on your MySites so that profile is correct.
Alot more information can be found by searching for sharepoint and multiple forests.