One good one picked up on, is people saying 110%, or indeed any amount beyond the actually possible 100%. This of course isn't limited to offices, sportspeople (football managers specifically) have been talking in terms of 150% percent and higher for quite a while.
I remember once the then-chancellor Gordon Brown saying he was 101% behind Tony Blair, to which people reacted 'What? Only 101?'"
http://news.bbc.co.uk/1/hi/magazine/7457287.stm