But that means you still have one connector left, right? Just buy one large disk...

The other option is to buy a PCI card with additional connectors. Must exist.

Yeah, I still have one SATA2 connector available, but I also still have room for 4 more harddisks.... (3x5.25).
If I get a 2 TB disk now I can go on for a while, but still, I'd like to be able to use the extra space when necessary.

I think I've found a solution.
1x PCIe x1 Dawicontrol DC300e ; SATAII controller, € 45
[img]/uploaded/18/5/dawicontrol_dc300e.jpg[/img]
1x Sharkoon SATA Quickport internal 3-disk bay. (fits in 2 5.25" bays), € 60
[img]/uploaded/18/5/sata_quickport_internal.jpg[/img]
Or alternatively this one: Lian Li ExH34A.
[img]/uploaded/18/6/123886.jpg[/img]
The latter is a bit cheaper, and uses aluminum brackets for better cooling.

This extends my case with 3 (or even 4) fastswappable SATA2 slots, and 2 extra SATA2 ports. [good]

Okay, it isn't cheap, but it's cheaper than an external SATAII enclosure (those start at 140 euros....)

-edit-

I've placed the order, with the Lian Li ExH34A case instead of the Sharkoon case. [:-/]
That gives me one additional position for a harddisk, making a total of 7 harddisks possible. [:)]
I added a 2 TB disk to start off with, and I can still add a couple of more disks in the future, without having to open my case. [good]