Hello im from Norway 25 year old, i came to Thailand in november on a single entry tourist visa, and will do my visa extend on immigration in january for another 30 days, but plan on staying in Thailand until May. I am wondering if it is still possible for me to go to Cambodia or Laos and get another tourist visa after this one and still get into Thailand.. Or is it some other way that will be better for me?

Please help and please explain to me so i can understand, im very confused about the new visa things going on.
sorry for my english.

Yes, you can go to Laos and apply for a new double entry tourist visa. That would be your only option.

Thank you, would this be best to do alone, or by a visa run company?

Go alone, in either Vientiane or Savanakhet you can use a visa agent.

You can find some useful info here: http://www.thaivisa.com/forum/topic/189375-latest-reports-of-getting-a-visa-in-the-region/