We don't just use ours for trips, we pack (almost) everything that goes in the freezer. Buy a large piece of meat and cut it into pieces suitable for the two of us and vacpac individually. Prevents freezer burn and makes life easier.
Morag and I do the same.
Saves heaps of $$ cash too when buying in bulk.
Saves loads of room in the fridge/freezer as well when packing.
Also nice to fix camping meals at home and just drop into boiling water as mentioned above in other posts.
We have had our el~cheapo ebay unit about 4 years now and it has never missed a beat.
http://cgi.ebay.com.au/VACUUM-FOOD-SAVER-PRESERVATION-HEAT-SEALER-460-bags-/260691974710?pt=LH_DefaultDomain_15&hash=item3cb273da36
We also only use rolls only so we can cut them to size.
We purchase the rolls from the same ebay sellar as they are usually heaps cheaper than buying them around here.
Bill and Morag