The Sony HDR-HC26 is a miniDV tape based camcorder. No surprises if you can't get USB streaming working.
ALL miniDV tape based camcorders transfer DV-format video by conneting
the DV port of the HD camcorder
to the Firewire port of your computer. USB
won't work. The "DV" in miniDV = Digital Video. It is as digital as the
digital video from flash memory or hard disc drive or DVD based
camcorders - only better because it is not compressed as much as the
Memory cards are not the only way to store digital video - and while not
as good as miniDV tape, memory cards are not as bad as DVD based
Firewire IEEE1394, DV and i.LINK are all the same thing.
If your computer does not have a firewire port, hopefully it has an
available expansion slot (PCI for desktops; PCMCIA or ExpressCard for
laptops), so you can add one.