I'll be arriving in Thailand on a 60-day visa issued by the Thai embassy in Sweden. I was planning to extend this by another 30 days by doing a visa run, but would it be possible to apply for a new 60-day tourist visa at the consualte in for example Penang or the Cambodia border? Or can the tourist visas only be issued by the thai consulate in my home country?

Tourists visas can be issued by any Thai consulate or embassy, not just in your home country.

Toursit visa is valid 60 days and can be extended another 30 days at the immigration, maybe an additional 10 days.

So before leaving home, apply for a Double Entry Tourist visa, or get another "TR" on your visa trip in Thailand neighboring country.

Thanks for the answer. Sorry if I'm a bit slow, but what did you mean by "TR"?

So, if I get you right, I'll just have to fill in another application for a tourist visa at the consulate by the Cambodia border. How long time will this take for them to process? Would I need to stay for days or would a half hour there-and-back journey be enough.  If I would choose the cambodian border for my visa run, would I need to obtain a Cambodian visa before I go? Also, is there any limit as to how many 60-day tourist visas can be issued to one person in a year?

TR = Tourist visa (issued by Thai Embassy or consulate)

A new Tourist visa can only be obtained at Consulate/Embassy, in Cambodia it is in Phnom Penh.

If you just do a border run, you will get 30 days, TR30, with a swedish passport.

Read more about border run under "Visa run" on the website.

There is many travel stories from other farangs on border runs, that tells you how it works.