Perfect Duluth Day

Old iMac + not-so-old MacBook =

We acquired an old iMac, went to upgrade the OS today and got an error about it not having an Intel processor …. we like the big screen and the prioress has a not as old MacBook she wants to DX for an AirBook.

(1) Is there any way for a common man to take the good parts from the MacBook and update the iMac?

(2) Are there any other suggestions for the old iMac? Can we load some flavor of Linux on it for the web-savvy here at the Mission?