Okay, I agree, this might be a noob question, but I am in a fix right now.
I am trying to test something, and I have 5 extra ipv6 addresses(native) lying around on a VPS somewhere(OpenVZ).
I need more addresses bound to a server(Xen) that I host elsewhere, which already has 3 ipv4 addresses bound to it, and it is using 1 of those for itself and two for OVZ nodes running on it.
Now because I can't get any more ipv4, I want to make use of those ipv6 addresses.
Any ideas on how I can do that?
Use an ipv6 address from somewhere else on my non-ipv6 server?

It is possible. You'll have to make use of IPv6 tunneling.

And is the same possible with ipv4?

Tunneling IPv4 through IPv6 works the same way as IPv6 through IPv4. In the reverse scenario the IPv4 datagram is in the payload of the IPv6 datagram.

After some light google.

http://en.wikipedia.org/wiki/List_of...tunnel_brokers

See also dhcpd tunnel broker on google.