UK transition altitude

[jason_beall]

Hi all,

I'm a US pilot who has just moved to the UK and I am trying to better understand REAl use of the transition altitude. In the US, transition altitude is way up at FL180, so most PPL's in the US never have to deal with it. Here in the UK, FL30 is the transition altitude. How many pilots actually set their altimeters to 1013 mb and use it say below 10,000 feet MSL? Or do most people just use regional when flying around?
Also, say I am flying south from Perth in Scotland and I am at FL35 and I am penetrating Newcastle's zone...do I stay on 1013 or set the Newcastle QNH in while transitioning?

Thanks for the clarification,

-Jason