Will a PS3 brought from usa work in uk ?

Yes ,definitely they will work since the PS3 are Blu-Ray based and Blu-rays are not regionally encoded.
So if you are planning to buy a PS3 from US and bring it to UK, then go for it .
BUT remember ---- You need a stepdown convetr for this too.Otherwise yo'll bloww away your PS3.Your US warranty will be entertained in UK.
Take the dip and feel the power of the PS3.

Will a xbox 360 brought from USA will work in UK ?

If you live in London and doesn't have a modern LCD television then i am afraid it would not , since all the USA xbox 360s are of NTSC formt. In UK all the old CRT televisions are PAL based.
But the slim and beautiful modern LCDs and plasmas are all format free.
So if youv'e got one then your USA xbox 360 will work for your.

BUT if you are just gonna plu your precious 360 right away STOP.
There are some points see should see before blasting off:-

1.Actually in USA they use 110V supply but here in London we use higher,so you will need to buy either a UK psu (£30 ish), or a 500 watt stepdown (£50 ish). Plugging the 110 psu into the mains here will blow it.

2.Xbox games are region locked.Games in UK are all PAL so they will not work in the USA 360.But there are some region free games available.You could find Region free games in London quite easily.So its all upto you.

3.And you could save a few bucks if you buy it from US as it dead cheap there.

4.BUT keep in mind that a US xbox 360 will have a US warranty,but in UK if you pressurize the Microsoft people and tell them some excuse, such as I didn't knew about US warranty funda ,then they easily give in and respect your warranty.Hah

If you mod it(I do not recommend moding ,I am against piracy) then you get region free games and pal games all over the net.(This was just for information people)
Modding voids your Warranty around the globe

Got Xbox or Playstion problems, MoDjUnKiE to the rescue.

Hi friends,
World has never been the same for me since i first laid my hands on the mighty PS1,
and since that day I haven't let any console pass by my fingers.

Due to my experience of having all the consoles first hand and having faced some problems related with them (I don't live in US, so there are some difficulties about repairs and so)and since i was able to fix them due to technical abilities so i am gonna share my progress over these heavenly consoles from now on.

If you have problems that are not listed on the blog, plz comment your questions in the blog, i check each of my blogs daily and you'll never be left unheard of(i have gone through that agony of not being answered).

Thanking you,
MoDjUnKiE