Q: External Hard Drives for 1.8 GHz PowerPC G5 with Mac OS X versions 10.5.8

Your G5 has FireWire ports so get a FireWire drive--much faster and your computer is bootable from a Firewire external if needed. I've tried the name-brand externals with overall shaky results. All I use now for our desktop Macs is this line, with the firewire option:

http://eshop.macsales.com/shop/firewire/1394/USB/EliteAL/eSATA_FW800_FW400_USB

Even the cheaper ones with FW400 transfer faster than USB2 in my tests. These are more than the weak sisters office superstores put on sale every weekend, but ask how much your data is worth. Most are USB2 only and come entirely too Windows-centric for my needs.

I have the one 1teraB one & works great on my iMac g3 w/ Tiger.

Robert