I've bought an asus eee pc T101MT and I decided I did not want to use a conventional hard drive as my main hard drive to save battery.
For this reason I decided to install ubuntu on an SD card.
So far I've used a regular kingston 4GB card but I'm planning on moving to a fast SD card once everything works.
As for this moment my system works correctly and quite fast and I keep my hard drive "powered down" most of the time.
I haven't noticed a big difference in battery usage but I did not try the regular hard drive for more than a couple of days before switching to the sd card.
What does not work is suspending the machine. More info latter on.
Most of what i have accomplished It's thanks to the general T101MT thread and as for the SD card instalation I've followed the instructions here (in spanish).
The steps are:
1. create a bootable usb with ubuntu. I choosed netbook remix. I really like the launcher but of course the instructions will work with any gnome based ubuntu (the optimitzation is not confirmed to be working in kde, sorry).
2. get an sd card. I guess a really fast card would help the overall performance. I'm planing on buying an 30MB/s card. If anyone has a better idea please say so.
3. install ubuntu as normal selecting the sd card as your target. Remember to place both the bootloader and the / partition on the sd card. I decided not to create swap space and only use ram.
4. optimize ubuntu to work on T101MT following the instructions on this thread [TODO].
5. stop the hard drive from starting on boot:
add hdparm -Y /dev/sda before exit.
gksudo gedit /etc/rc.local
If you've done the T101MT optimitzation the file should be like:
6. change the record of access times to something less stresful for the card than realtime.
#blah blah blah
hdparm -Y /dev/sda #spin down hard drives
setpci -s 00:02.0 f4.b=ff #set brightness to hardware max
twofing --wait #start screen multitouch
gksudo gedit /etc/fstab
seartch for the row with / as the mount point and change realtime for noatime.
It shoud be something like that:
Until now I had errors=remount-ro as an option but I thing it made my system mount on read only after sleep. I'm trying errors=remount right now. I'll follow up with some conclusions once I've tested it.
UUID=46fcfdb5-ead8-4cdc-971c-e9558ade2ac3 / ext4 noatime 0 1
don't close fstab yet...
7. make the logs write to ram.
in fstab change the tmpfs lines to that:
tmpfs /tmp tmpfs defaults 0 0
tmpfs /var/tmp tmpfs defaults 0 0
tmpfs /var/log tmpfs defaults 0 0
8. Change the hard disk access optimization from elevator to none.
Copied vervatim from here.
Edit /etc/default/grub using your favorite editor, and add "elevator=noop" to the list of GRUB_CMDLINE_LINUX_DEFAULT values. The corresponding line will then look like:
GRUB_CMDLINE_LINUX_DEFAULT="elevator=noop quiet splash"
Then rebuild GRUB2 configuration files:
$ sudo update-grub
9. Optimize other programs.
I use firefox without cache to avoid multiple writes to the sd card. To do this just write about:config
Right now I'm having some problems sleeping and hibernating I guess it's mount options and t101mt drivers fault respectively. I'll follow up with solutions when i found them.
I would be very glad of any suggestion you think of and to answer any questions but I must say in advance that I did not came myself with anything wrote in this post. That I just wrote it all together (and it may contain errors of my own to).
i hope this steps are useful to someone and also to get new ideas on how to improve the T101MT on a SD card performance.
 My T101MT has 2GB ram and I think that being a netbook and not planing to do anything resource intensive on it It can go without swap. I don't want my SD card to get worn out with the multiples accesses the swap space would do. I think that in newer versions of ubuntu there is no problem in no having swap space at all. Please correct me if I'm wrong.
 right now I have working. Multitouch screen, multitouch trackpad, rotate screen, full birghtness, photo camera. I don't have hibernation or video recording working.