I purchased this VPS from HostFolks for testing IPv6. The VPS came with a handful of IPv6 addresses in addition to the single IPv4 address they normally provide. (Be sure you ask for a server in Germany, or verify that the VPS does have IPv6 capability – not all their sites do.)

IPv6 really “just works out of the box”, unless you need to do something tricky on your system. The web server, ssh connection, etc. all acted as expected. I did have to add special configuration (udp6) for the SNMP agent, but that’s a pretty specialized configuration.

Update – August 2019: Alas, hostfolks.com seems not to be in business, but virtually all VPS providers can now handle IPv6. (In fact, run away if they don’t offer IPv6.) I’m hosting this site on Ramnode.com now, and use it for all my VPS systems…