The British Philosophical Association exists to support and promote the study of philosophy in the UK. The BPA welcomes Philosophy PhD students as members; you can join online for just £8 per year. Membership of the BPA entitles you to a range of discounts on books and journals, including 20% off OUP and Routledge books, along with free membership of the Institute of Philosophy. By joining the BPA, you'll also be helping to support their activities.
For more information, visit the BPA's website at www.bpa.ac.uk.
NB Please note that the British Philosophical Association (BPA) is a distinct association from ourselves (we have an extra "p" in our name because we're the British Postgraduate Philosophy Association.) No doubt we'll one day perform our own version of Monty Python's "People's Front of Judea" sketch at the Joint Session :)