When to use namespaces

Hi everyone,

I'm doing a small hobby project to better my understanding of php5, 
specifically php5.3 and I'm wondering when a namespaced project is 
better and when it is better to simply use a prefix to all class names.

I've been trying to get a feeling for what is considered the best 
practice, but most of the pages dealing with namespaces start with the 
assumption that you are building a complex application with lots of 
modules and say things like:

Namespaces should be all lowercase and must follow the following conention:
    <vendor>\<package_name>\

(thats from the php.standards mailing list btw)

In my case the project is a single module, single php file, with about 6 
classes. It is an OO wrapper for PHP's xmlrpc methods (client and 
server) and meant to be used in a number of different projects.

Is it considered a good idea to use a namespace in such a case? And if 
so, what should that be? I've named the project 'ripcord', and used that 
as a namespace as well. I could probably name it 'muze.ripcord', but 
somehow that feels less 'open' to me.

Thanks in advance for any thoughts,
Auke van Slooten
Muze (www.muze.nl)

PS. The project is at http://code.google.com/p/ripcord/, the PHP5.3 
version is at 
http://code.google.com/p/ripcord/source/browse/#svn/branches/php5.3