Answer (after writing all the crap below): I use 8 fingers to type, but all 10 fingers have some use on my laptop).
hmm its hard to tell without actually typing something, so here is something useless to type about whilst I watch my hands at play but not actually looking at the keys they are hitting, wow this is really fun especially when I am making mistakes.
Going from my right hand (small finger) to left hand small finger (from 10–1):
10 – return key
9 – delete key
8 – rarely use /edit I actually use it for the up/down arrows when using the arrow keys
7 (index): – most of the right hand side of the qwerty keyboard including keys 7 to = besides above
6 – space
5 – rested on space but never actually hits it (I am right handed so might explain why) /edit I actually use this to hit the left mouse button on my laptop (when I am not double clicking the mousepad for some reason such as scrolling on a page (where my index finger is scrolling on the mousepad).
4 (index) – numbers up to 6, and with 3 and 2 they type most of the left hand side of the keyboard
3 – see above
2 – see above
1 – caps lock, shift, ctrl, fn, tab
What is interesting is where peoples range are for each hands mine seems to be around bhu on the qwerty keyboard – where I type bhy with my right hand although the y is slightly debatable depending where my hands are at the time (ie typing “typing and my left hand would be typing the y, but typing “dye” and my right hand would hit the y).
Its probably more complex than this, and more based on where my hands are at the relative point of typing a letter, but this is based on 5–10 mins worth of observation.
Hope you enjoyed the wonderful indepth analysis :D