Gigabyte hands down. The Asus T91 has internal battery meaning you cant buy additional batteries for it and just look at the hard drive difference. 160GB with the Gigabyte and what does the T91 have? Not much at all.
You can tether your mobile phone 3G with any of these netbooks and wala! you got internet on the go. You can even tether you mobile phones internal GPS via bluetooth with the netbook and poof! you just scored yourself a 10 inch navigation system. You can even use Skype on the netbook and use tethered 3G from your mobile and boom boom pow! you can now call international mobile and landlines for a fraction of the cost to use your normal mobile phone.
And dont even get me started with what you can do with the touch screen. Although not multi touch like the iphone... you can still use it for some niche apps like virtual dj etc. Can you imagine a virtual turntable? Thats just some of the things a netbook/tablet + bluetooth + 3G + GPS can do.