Is there anyway to do this?

Yeah, look at the patch.txt for patch 1.15.2.

I've used an .iso disk image to replace my CD on both PowerPC and Intel Macs without any difficulties.

Doesn't the latest patch automatically make it a CD-less program?

Before I bought my PC, I seem to remember updating SC and never having to use my CD.

EDIT:
Yep, here is is:
Mac users:
- If you own only StarCraft, copy "StarCraft Archive" from the StarCraft CD to your StarCraft/StarCraft Files/ folder.
- If you own StarCraft: Brood War, copy "Brood War Archive" from the StarCraft: Brood War CD to your StarCraft/StarCraft Files/ folder. If you wish to play the StarCraft original missions then please copy the Starcraft Archive file from the original StarCraft CD as well, as listed directly above.