Expand the memory of your iPad / iPhone / iPod Touch

Seagate has a 500GB drive which works on the same principle.

http://www.amazon.co.uk/Seagate-Satellite-Portable-Rechargable-Wireless/...

Hitachi G-connect also has a 500GB drive

http://www.g-technology.com/products/g-connect.cfm

These products have received lukewarm reviews.

Anyone using any of these?

Just found the answer. Even though you have to connect your iPhone, iPad or iPod touch to the Wi-Drive's Wi-Fi network, you can still get online when you're using the drive, because it can connect to a nearby Wi-Fi network and feed the connection through.

Sounds interesting... Though with cloud services, you've inherently got more storage if you can connect to a wi-Fi network. But this could be good for taking extra music/movies on hols? One to check out!

I use yet another option which is half way between the two above - Western Digital My Book Live.

This gives me 1TB of network storage, which is easily accessible via WD's own iphone/ipad apps.  You get a Mionet account when you register the drive and you can access you files from anywhere via wifi or 3g. You can also get one for about £85 at present from Dixons.

Im not sure why you would want a wifi drive, rather than a usb sd-cardreader.

It is only going to last so long because the wifi will drain the battery or both the drive and the phone.

Also wifi throughput on Iphone4/Ipad is not very good at only 30Mb/s, compared to a minimum write speed of at least 80Mb/s and read of ~200Mb/s for a SD card (usb).

Wouldnt the camera connection kit be better?

It depends on your requirements. If you're sitting in a conference of 5 people who all have iPads, then documents in the wifi drive will be accessible to everyone simultaneously. I think up to 3 iOS devices can access media content simultaneously.