As a PhD student in the life sciences, there are plenty of professional/scientific societies vying for me to join them. These range from the very general, covering all science such as the AAAS, through the general biology (Society of Biology) down to specific fields (Biochemical Society) or techniques (Royal Microscopical Society). Most seem to come with a student rate, subscription to the society’s journal and some obscure postnomial letters. Perhaps most importantly, becoming a member often entitles you to apply for travel funding, as hapsci pointed out.
On the other hand, joining a society requires outlay of some (normally small for student) membership fee, pestering your PI to sign a form stating you are student of a relevant discipline and for the travel grants, anticipating when you want to travel as some societies require you to have been a member for some time prior to asking them for money.
So I’m putting it out there; is it worth joining these societies as student, and if so, how many?