Yep, that is me.
I have far less than a pound left on my Intersango account, which would be shameful to withdraw so decided to experiment:
I do tiniest bids. For visual interference only.
Not close enough to ask to get swallowed and late enough at night to survive as long as possible. Maximise the chance of not being fulfilled and hopefully hinder common thought process (men (which are most Bitcoin speculators) are visual creatures and influenced highly by seeing numbers/graphs/fat arrows/etc.) Once fulfilled, do correspondent higher than average asks to push unwanted numbers up/down the table/graph as I choose.
So can I get the price above £5 ($7.9) if I so choose? You bet.
https://bitcointalk.org/index.php?topic=57034.80 (‘cause I did not, but hope there was my influence, however small.)
Now. If someone is to use a bot to do these ‘noise’ trades back and forth to effect the price/charts at least visually they can manipulate this market (to a degree) pretty safely with a minimum of costs (that is until a minimum transaction amount it enforced by the exchange – not very likely now or charts sites remove all ‘noise’ by default – again not yet likely).