What is the minimum number of people that would have had to have been
involved in a conspiracy to manipulate and/or alter the results from
electronic voting machines on a scale large enough to have changed the
outcome of the recent presidential election?

There is an interesting article in www.wired.com that talks about
e-voting machine fraud in florida:

http://wired.com/news/evote/0,2645,65665,00.html?tw=wn_tophead_1

With the elections being so close, you would only need to manipulate
e-voting machines in populous counties of important states, such as
Florida and Ohio. And for that you would only need a  3 social and
computer hackers per polling location, plus 10 remote backup
supporters per county. So that would be:

( P x 3 ) 10 = n

P = Polling location
n = number of people

But that is just the infantry, you would need to take into
consideration the commanders and financial supporters. Which in total,
I'd see it would be about n+50

i would like to clearly establish the fact that i am no expert and i
am aserting everthing in this post.

first off, the voting machines im asuming you are refuring to the elctronic ones.

there are 3 posible ways it could have been rigged that i think are
realistic(i am not saying eathr of them happend just that they where
posible)

1 person required some sort of programing superviser

1 person per polling place i estimate 300 people in total. if you
where to do somehing physical to the machines.

only a few people who "hacked" a few machines at a few key voting
places in a few key states, i estimate aboout 50 people in total.
I am asuming u are a democrat becouse i dont know why you would be
wondering otherwise
the following is all my opionion do not flame (atack) this post,
i do not know why u are wondering, but as a extreamily active
democrate i would like to say pleese pleese, spend you time doing
something to help the cause, instead of complaining about a rigged
election, the election of 2000 was stolen from the democrats the 04
may or may not have been. but kerry conseaded meaning he admits he is
defeated and we should work, as hard as it may be, on dealing with
bush for his next 4 yrs. then in 3.5 yrs go out and campaign and help
you cause