[Noseyears]

A couple of interesting alternatives on the cheap side,

Ha Info U2

And this one, (Diy)
http://www.minidsp.com/products/ministreamer

If you guys know more options, you can add on the list.

[WC]

Here is what I use.

ADS Tech RDX-150

Doesn't do hirez, but that doesn't matter to me at this time. I use it between my netbook and Marantz AVR. USB to Toslink.

[gooberdude]

I've had the $99 Consonance converter for a few months now, definitely an improvement.  Available thru grant fidelity.   

no affiliation

[Noseyears]

The Musical Fidelity V-LINK can be found for around $80 on ebay, its also a nice solution for PC users with limited bandwidth (Via USB) on their Dac's.

[boynamedsue]

The new version of the audio-gd digital interfance is pretty good, and I believe is async. The price ranges from $108 to $198 depending on options. Impressions can be found on the audio-gd DI on headfi.

[Noseyears]

Thanks!

A small and nice looking converter from matrix electronics (chinese i think)
http://www.matrixelectronics.net/matrix-24-bit-96-khz-usb-to-coaxial-converter-p-197.html