Wine bottle?

stik a teaspoon in the bottleneck. make sure it doesn't touch the wine. i don't know why but it really keeps it fresh even for a few days

often I can turn the cork around and insert the other end. If not then cover the top with plastic wrap or similar and rubber band it. Another idea is to just take it out of the bottle and put in the smallest sealable container you have like another bottle.

This may sound plebby or pikey but cling film over the end should do for a day and night perhaps but even without anything over the end it should retain its flavour unless put near strong smells and flavours like garlic and onions when placed in the fridge.

If you put the cork in some very hot water, leave for a few minutes, it will easily fit the bottle...howszat ? easy..!

Sounds weird but back when I was a student we used to put some clingfilm over the top and secure it with an elastic band. Didn't work too bad...

You can buy them tops at the wine shops that will do, if not just drink the whole bottle;)

a carafe with a stopper would be good, but drinking it would be best. Most wine just won't keep that long after opening, especially bubbly...

Blue-tac

You can buy a patent device for this purpose in most supermarkets, its really for pop bottles though i do know they do the job you require as i use one for this purpose.

Clingfilm!