driving common anode 8x8 matrix using arduino mega?

ive been doing some poking around and basically what im looking at doing is driving a simple, one colour or even bi colour matrix using a arduino mega 2560, im thinking that it might be impossible to do since the matrix is common anode and not cathode, or does anyone have a fair idea on how to acheive this?

i have dabbled a little bit but i wasnt able to draw letters or anything on it because as soon as i turn on a column, any other rows i turn on, the LED comes on in that active column instead of being able to individually address each LED, i did originally try to accomplish this with a rainbowduino and attempted to program that through a arduino UNO, but i couldn not obtain any help so i threw the rainbowduinos into a storage box to gather dust

Driving a common anode matrix is similar to driving a common cathode matrix, just need transistors on the “other side” of the matrix to control the multiplexing.
You will need PNP transistors between the mega pins and the matrix columns to control the current into the common anode, and then 8 mega pins with current limit resistor to sink the 8 cathoodes in each row.
The multiplex is simple - drive the cathodes, turn the anode on for column 1, pause some few mS , then off.
Repeat for colums 2-8.
Data to be written can be pulled from an array:

for (x=0; x<8; x=x+1){
cathodes = column data
pulse anode on, off
}

See this for a discussion of the options.
http://www.thebox.myzen.co.uk/Workshop/LED_Matrix.html