Newbie: ULN2803, switch positive and negative?

Newbie question, haven't got much electronic design experience. I'm redesigning a circuit for a friend, and he's got 52 NPN transistors on this thing .
I'm wondering if I can swap them for several ULN2803 ICs. I know it's feasable, but he's got each transistor switching a positive voltage on and off. All the datasheets I see for the 2803 show it switching the negative side. Is there any other chip that can do this for me, or can I switch the positive and negative pins on the 2803?

Or does anyone have any other suggestions?

Basically, this is what he's got:
**broken link removed**

This is what he wants:
**broken link removed**


Will that last circuit actually work? All the data he's got is saying that the output on the right side of the pins will be a (-) connection

I don't know what you're talking about. Please post a schematic and I might be able to help.

The uln2803 is only capable of sinking current, not sourcing. You'll have to use a different transistor array.

Can anyone suggest a good replacement for this then?

how much current does the circuit need to handle?

EEK!
Most of the polarities are backwards on your schematics.

EEK!
The LEDs don't have current limiting resistors.

That was just tossed together to demonstrate what I wanted to do, I always put resistors on my LEDs (except once, and it actually made an audible 'pop')

Circuit only needs to light a LED (25-35ma @ 3.2 volts)

I just don't feel like hand soldering 50+ transistors into place. And plus, it would just look a little cleaner

Use a few ULN2804 ICs. Its outputs sink to ground when turned on and the inputs work well from +12V.

oh, all you have to do is turn the leds around, connect all the anodes to +12V then connect each individual cathode to an output of the uln2803. Putting current limiting resistors in there of course.

Someone, on another forum, suggested I use the UDN2985, trouble is, can't find a supplier for it. Anybody got any ideas?