http://cc.jlab.org/cgi-bin/quotacheck.cgi
What they don't tell you unless you ask (or browse) is that the same info can also be obtained from the command line:
/site/bin/quota [username]
Example:
% /site/bin/quota adaq user adaq home - 4813112 10485760 52697 - adaq This information is updated every 10 mins
This command only works on machines that can mount /group, so don't try this at home ;)
A copy of this log entry has been emailed to: rom@jlab.org