Temporary tables

Hello,

I am attempting to optimize a number of queries that are dependant on a
first query (big join) that is expensive to run.  Instead of having the join
be executed for each subsequent query I would like to put the results of the
first join into a temp table.  I found syntax for creating a temp table in
the idocs (SELECT <foo> INTO <tmp_table> FROM <table>) and this works fine.
My problem is that the table isn't very "temporary".  Is there a way to have
the table drop automagically when I'm done with it.  I'm accessing it
through PHP 4.0 via apache on a 7.1.3 db.  I would really like it to drop
when I close the connection.  

A 2nd question is what about concurrency?  Is there a way to hide this temp
table from other concurrent connections to the db (I thought I remember
reading an earlier post about this) so that you don't get name conflicts
with the temp table?

Thanks,

Mike Shelton