I'm planning on visiting a lab during my trip to another country. I'm just getting my PhD, so I'm not a student anymore, and maybe not experienced enough to be a visiting lecture. Visiting students, visiting lecturers or post docs might be welcomed, but I'm not sure for my case.
Is it okay to e-mail to possible labs if people like me can visit the lab(s) for about a month? What is expected in return? Do we have to give a talk, or produce some result? Or is it okay to just learn from them, without directly contributing anything?