Share your experience!
Xperia Arc 2.3.4 (4.0.1.A.0.283) Update Available for both LT15i LT15a (thanx BR4DOKYBrazil for the link and XDA forum datagubben for the file)
http://forum.xda-developers.com/showthread.php?t=1269910
Global Generic version
http://forum.xda-developers.com/showthread.php?t=1269937
LT15a (american version)
http://forum.xda-developers.com/showthread.php?t=1319764
Here are some screenshots/pictures:
I have the new firmware 4.0.1.A.0.238 LT15i updated via PCC today.
Seems snappier (wishful thinking).
3D panorama (Did not work yet for me).
3D gallery app.
Screenshots in power menu.
New time widget.
Facebook share integration stuff.
Swype keyboard.
Here is 4.0.1.A.0.238 Nordic_Telia.ftf for flashing:
get the Flashtool From here
http://forum.xda-developers.com/showthread.php?t=920746
Install it and you will see 5 folders
Custom
Drivers
Firmwares
Loaders
X10Flasher_lib
take the firmware to the "Firmwares" folder
click on Falsh
Press Ok
it will ask you to connect your phone on Flashmode (turn off your phone, press the back button, then connect the USB) press OK
This is an step by step guide
as usual more pictures coming soon, in the mean time I'm using xda and xperiablog's pictures
have u updated yet ?? 
Make sure you backup everything
Use one of these links to download the Backup & Restore app
http://forum.xda-developers.com/showthread.php?t=1193802
or
http://www.elita-clan.com/downloads/backup_and_restore_v010935.apkhttp://www.elita-clan.com/downloads/backup_and_restore_v010935.apkor
http://www.mediafire.com/?1n07llajeaoo03y
How to install it
You need to
go to settings -> applications -> check unknown sources
download IO File Manager
https://market.android.com/details?id=org.openintents.filemanager&feature=search_result
download the backup & restore app, transfer it to your SD card, use OI file manager to find it -> tap on it -> install it
Contacts
just to play it safe sync your contacts w/ google if you haven't already
open your phonebook
Don't worry so much about backing up your apps
on your computer go to
market.android.com -> log in -> click on My Library -> and send all your apps to your phone
SMS/MMS
if you don't want to use the backup & restore app then
Install "backup SMS" to back up your SMS and MMS to your Gmail
https://market.android.com/details?id=com.zegoggles.smssync&feature=search_result
or your SMS use
"backup & restore SMS"
https://market.android.com/details?id=com.riteshsahu.SMSBackupRestore&feature=search_result
or for your MMS use "Save MMS"
https://market.android.com/details?id=com.schwimmer.android.mmsextract&feature=search_result
Call Logs
And for call logs this is great
https://market.android.com/details?id=com.yang.android.ansta
dude.....i updated ma phone Re: Xperia Arc August Update 4.0.A.2.368 (If you don't/can't wait) (LT15i & LT15a) with this link u provided me in august....now ma pc companion is showing a new software 2.3.4 update...but when m clicking on update option ...its showing error? any help wats d proble........is this bcoz ma phone lost its orginal rooting coz of using flash tool....help me out in this asap plzzz
first of all it cant show 2.3.4 cz its not released yet :smileygrin:
it'll release in october..
and yeah since u already did the flashing of 2.3.3 and firmware 4.0x i think u cant do it..
but yeah..
if u get an official update of 2.3.4 u can update it 
just check it again and see whats the new update it is showing 
Well I have update my Arc to 2.3.4 (4.0.1.A.O.238) using PC Companion. Everything took 15 minutes and went smooth.
- 3D panorma/3D gallery
- New wordtime widget (looks nice together with the "old" weather widget
- large letter at the key-board
- some integrated Facebooks application
- some new maps
- if the screen is more sensitive/responsitive cant really tell
As mention earlier there is no bigger changes - or improvment, but even so it´s nice to see that Sonyericsson has got better and better to be before up date schedule rather than behind.
Nice work Sonyericsson 
Very nice uliwooly-wooly !!!!
it works just fine