Not Enough USB Ports

[slaughteredlamb]

My iMac has 3 USB 2 ports on the back and it's keyboard also have 2 USB ports but these are USB 1

Presently I have everything connected as follows:

Mouse to Keyboard to USB 1 on back of iMac
Drive 1 to USB 2 on back of iMac
Scanner, printer, card reader to powered hub to USB 3 on back of iMac
Drive 2 (Firewire) to External DVD (Firewire & USB) to Firewire 1 on back of iMac
Drive 3 to Firewire 2 on back of iMac

I also have an iPhone which doesnt like being connected via a hub and so when I need to update or sync it I disconnect the hub from USB 3 and plug the iPhone in directly.

Drives 1 & 2 I use all the time and must be able to use both drives when syncing to my iPhone as both drives contain iTunes music and video files.

The problem is that I now want to replace drive 2 with a USB drive I have which is much larger capacity. This new drive is of the same type as Drive 1 which doesnt have an on/off switch and simply powers up and down with the iMac. The trouble is that if you plug these drives into an Active Hub they don't shut down because power is still going to the USB bus and it thinks the computer is still on.

Any ideas how to connect all that up in a way that USB 2 speeds are maintained on the devices that need it and I can access Drives 1 & 2 with my iPhone. I'm prepared to buy other hubs or hardware to make this happen, I'm just not sure if it is possible?

[slaughteredlamb]

Would this be a workable solution?

Non of my USB devices with the exception of the card reader and iPhone are bus powered i.e. they all have their own power supply so nothing should really be drawing any power from the USB bus should it?

Therefore could I not do the following:

USB 1 > Unpowered USB Hub > 2x USB drives
USB 2> Powered USB Hub > Scanner, Printer
USB 3> Keyboard & Mouse

When I need to use the card reader or iPhone I could unplug USB 2 and use that. If USB 1 is connected to an unpowered USB hub than shouldn't both drives power down when the Mac is switched off unless the fact that both drives have their own PSU's means that power will go into the hub from each drive and therefore keep the other drive on and vica versa when the Mac is shut down?