that is the longest I know http://www.antstore.net/shop/product_info.php/info/p425_Kanuele-0-8-x-120-mm.html you can get by a doctor.
There are longer ones, but I've seen them only in labratory
Thanks dr house i shall be on the lookout :) unfortunately paying €30 delivery for a €0.5 Euros item is a bit too much (just a bit ;))
Not to mention i am looking for something along the lines of 10cm :S
your local drugstore ? Ask if you can have just one ? Maybe if you are really sweet, they will give it to you. ;)
You could try using the needles that you can use for refilling ink printers.
They work for me.