Yeah, they don't use anything, unless you mean decimal parts.
Most people don't separate thousands, etc when they are writing them by hand, at least over here, and if someone seriously feels the need to do so blank space is enough.
Officially 'comma' or ' , ' is used to separate decimal part over here but it is really a liberal thing - comma and dot/point is used commonly and they are interchangeable.
Hmm I think that this thread should also cover our traditional Troll-topic - day/month/year writing system.