We've been added to Poollo, check it out here:
You only need your Groestlcoin address as username, no need to register: http://poollo.com
There are 3 different ports for different difficulties:
stratum+tcp://poollo.com:11008
stratum+tcp://poollo.com:11032 <--- Vardiff
stratum+tcp://poollo.com:11256
The 32 one is auto adjust between 8 and 512 with target Time: 15, retarget Time: 90, variance Percent: 30
Fees are 0.9%, and payments are calculated and automatically sent to the wallet mining address every 2 minutes.
Poollo are beta testing with the NOMP multipool capabilities so we can have a groestl multipool switcher.
Generating your private key will be here: http://poollo.com/key.html and you will be able to multi mine groestl based coins.
Currently, in closed beta testing phase, the coins included for groestl profit switching are Atheistcoin, Aidbit and Dokdocoin.