##Non-Combat Turn Order##
Non-Combat Turn Order
I've used this idea a few times with my groups, either in situations like you described where everyone seems to have their own thing going on, or when I really need to know exactly what everyone is doing at that exact instance (cough Tomb of Horror cough). I find it helps keep things moving and prevents the group's antics from makes sure every party member has a chance to do something.
Essentially, when the group starts acting like you describe, tell them that you are going into a very loose version of the combat round. Since I usually run D&D 3.5 games I'll use that terminology, but the same basic principal can be applied to any system.
Starting with Player One, each player gets a move action and a standard action. The rules for these are much more relaxed than a typical combat round, but I still place some restrictions on what can be done in a turn. This helps players realize that some actions take longer than others. So if Player Three wants to check their supplies and put on their goggles, that only takes a round. Depending on the wacky roleplaying Player Four wants to do, that might take 2 or three rounds. It could also help Player One see exactly where he is in relation to the other party members as he goes to scout, since they has a set move speed per round. The important thing is that everyone gets a chance to act how they see fit.
This technique can be helpful, but I wouldn't and don't use it all the time. If the party is all standing around acting wacky then feel free to let them just go at it and roleplay. But if every party member wants to do something different and it is bogging your game down, this might be a good way to let everyone do their thing without it taking too much extra time.