can you move a pumpkin once it has started flowering/fruiting

If it doesn't kill it, it will check it's growth. Don't move it. If it's one with small fruits then you could try training it upwards on to a wigwam or similar to give you more room. They are big plants arnt they!!

Realistically you can expect to dig something up when it is fruiting and expect it to carry on growing as if nothing had happened. As Sid suggests create a wigwam for the vine to grow over unless the fruits are already quite large.

Erm...Moongrower - was that actually what you meant to say...?? LOL

Um yes...