It appears to be a patent on having two list pointers in a structure (auxulary pointer so you can sort the list in a diferent order). Funny even the linux kernel has a really fancy (arguably patentable) way of doing this using very simple macros. Though yes this could also cover doubly linked lists.

For prior art I'd give /usr/src/Linux/include/scsi/scsi_cmnd.h - struct scsi_cmnd: Belongs to two doubly linked lists, though not for storing in diferent orders, it's because that structure happens to have mutiple systems tracking it.

This is probably a patent from some engineer who's been pushed by his boss to come up with things to patent because he's not done one recently. Personally I'm accredited on a couple of software patents, but being UK ones, there is a fairly heavy ammount of proof that this is a concept of tangable value, eg you can't patent a linked list because it's not going to do anything, but you could patent an application of it which makes the thing your product does do it better/faster/etc.

So does winGaim. When you open the plugins dialog box it just start at the right directory though