In article , Padger
wrote:

Some time ago I had a cylindrical piece of material which you inserted into
a standard black plastic refuse sack.
This held it open while you filled the bag up. A great hands free gadget. I
got mine at Hampton Court Flower Show but have been unable to locate a
supplier since.

I can recommend this (apologies for long url):

http://www.lakelandlimited.com/is-bi...CS/Store/en/-/
GBP/DisplayProductInformation-Start;sid=z3dtqCcRU3flqGWIhyRhro_RcsJ42sC9
mUk=?ProductID=SwDAqAYUUcAAAAEBDtdJjaP9

Also excellent for rubble disposal - the 'neck' stays in place until
released, even when carrying heavy waste around.