[dimestock1]

I was wondering if this is possible:

I have a vga cable, and was wondering if somehow I could connect both my Powerbook and my iMac 450mhz blue together and use the iMac's display or dual monitor from my powerbook.

Laymans term:

connect powerbook to imac using vga, can i use the imacs display?

[mduell]

No.
You can do it over an ethernet cable using VNC, but it's a bit more laggy.