<p>I'm interested in grabbing the EPG data from DVB-T streams. Does anyone know of any C libraries or an alternative means of getting the data?</p>

tv_grab_dvb can do this. See the
subversion repository
for sources.
tv_grab_dvb is made to work with the stream grabbed from the DVB-T card using
dvbtools
on Linux, but it may be portable to other platforms - I think it just works with the raw data from the stream.