Pulling a standard-definition MPEG 2 movie of 1h 55m 58s duration straight off a DVD took Turbo.264 28m 23s to rip and convert to its iPod Standard pre-set. Setting HandBrake to match Turbo.264's settings - 320 x 240 resolution, 128Kbps 48kHz AAC audio, 768Kbps encoding rate, 30fps - ripped the same video and saved it as an H.264 file in 59m 33s, a little more than twice as long.
More up-to-date Macs than mine will see a smaller differential, but while processors are improving, it's still going to be some time before the Mac's own CPU can match the Turbo.264's encoding speed. And the Elgato product costs a fraction of the price of a new Mac.
Converstion to H.264 also produces files a fraction of the size of the original, from 1249.3MB (1.22GB) down to 136.9MB in the case of the Apple TV pre-set and even 31.1MB with the iPod Standard setting. That makes the Turbo.264 handy for folk who've digitised their old VHS tapes for burning to DVD and would like to keep less drive-stuffing back-up copies.

Elgato's Turbo.264... and friend
The only flaw with Turbo.264? It's a Mac-only product. Elgato's cagey on Windows support - it might happen, it might not. If it doesn't, there's always ADS' Instant Video To-Go, or apps that make use of the host PC's graphics card to process the video data.
Some users may also find the lack of flexibility irritating. To keep its app user-friendly, Elgato hasn't equipped Turbo.264 with custom compression settings, but an Advanced... section would surely have been easy enough to add. Maybe it will do so in the near future. While the Turbo.264 is so clearly aimed at consumers, video pros are likely to find it handy too, and as they provide feedback to Elgato, I'd expect it to start adding more pro-friendly features.
And there are plenty of devices in addition to the PSP, iPod and Apple TV that can play back H.264 files. Their owners should check out the Turbo.264 too.
Verdict
A couple more CPU generations and the Turbo.264 will be redundant, of course. But why wait three or four years for H.264 encoding speeds you can have right now, for a fraction of the price of a new Mac? And the results speak for themselves: Turbo.264 pumps out iPod, PSP and Apple TV-friendly video in a fraction of the time your Mac can. If you use one of these devices for video, Turbo.264 is a must-have.

Elgato Turbo.264 H.264 encoder
COMMENTS
Same(ish) thing for PC
The same soft of gadget is available for the PC from ADS, called the "Instant Video To-Go".
Re: That's all well and good, but...
I think a lot of people are missing this part of the review...
"The connection to QuickTime means that the Turbo.264 is accessible by almost any application that uses Apple's multimedia software to encode video, not just Elgato's own - Turbo.264 shows up in iMovie, for example. Content is decoded then re-encoded by the Turbo.264, so any format QuickTime understands, even via a third-party plug-in like Flip4Mac's WMV add-in, can be converted into H.264 format. If the Turbo.264 isn't connected, you'll be told to slot it in."
I read this as I can use QT7 to export and still take full advantage of the H.264 hardware acceleration. I believe this also means that applications like Toast will benefit because it uses QuickTime to process video too.
You should also be able to sey up custom output resolutions
re: PSP users avoid
According to my take on this article You can also use QuickTime to export to H.254 and set up a custom output quality. That means you should be able to take full advantage of the PSP's video capabilities
h264
768x576 can easily be "widescreen" if it is encoded anamorphically. Your "widescreen" DVDs are encoded at 4:3 NTSC or PAL resolution but are flagged as anamorphic and the DVD player/screen just stretches then accordingly.
Also 768x576 should be okay for turbo.264 From the data sheet as long as the size is below 800x600 (and 768x576 certainly is) the image is not scaled. Only video above 800x600 will be downsampled.
I've just ordered one of these and I'm sure I'll see an improvement in encoding times even on my 2Ghz core duo iMac. As far as I can see what is happening is that Quicktime has to do the decoding to YUV from the source file in software with the GPU. There will be no way the elgato can do the decoding from the miriad formats QT supports so will have to be passed a common format (this is usually 4:2:2 YUV I think) This will then be passed to the elgato which then sends it back as h264.
Either way you look at it some of the encoding will be taken off the GPU which then allows it to have more cycles for the decoding/bus transfers etc. It really is an h264 co-processor.
RS
Re: PSPs
Joe K may be correct that the PSP's screen is higher than 320x240. However, if he hadn't installed cracked firmware on his machine, he'd be aware that you've got to encode at this resolution for Sony's bundled player to support your file - the company reserve full resolution playback for shop-bought UMDs.
