Using LDAP to share users among Linuxes

[Tuomo Pyhala <tuomo@kase.fi>]

I was wondering how to use LDAP to share user accounts between linux
boxes. Does that make even any sense, should i just setup NIS? I've
understood that maybe some other software could also use data in directory
(for example FireWall-1 supports it?).

It seems like there would be open source components for all tasks, i need
to download 

1) OpenLDAP
2) nss-ldap module
3) pam-ldap module
4) Migration scripts

It seems that there are modules+migration scripts available at
www.padl.com as well as at www.rage.net. Which one i should use? Does
anyone know if i can implement anything like nis netgroups (mainly for
grouping users reflecting organizational structure somewhat) when using
these modules?

How about security, as far as i understand the ldap-solution doesn't
hide hashed password from users? How could i implement hiding? 

I also noticed that there are problems compiling OpenLDAP with glibc-2.1
included in RH 6.0 (Has been discussed this list before, strdup defined
as a macro which conflicts with definition in openldap 1.2.1 sources). Is
there a patch, or can i use precompiled binaries from local redhat contrib
mirror?