Hi I am a N00b to android phones and I just got a SONY Xperia X8.
I managed to get Link2SD working on my X8 after much research.
Here is how I did it.
DISCLAIMER: Please use the info below at your own risk with no warranty of any kind.
Step 1: Backup your SD Card
Step 2: Update your Xperia X8 to Eclair 2.1 using PC Companion
Step 3a: Root your Xperia X8 (Eclair 2.1) - use SuperOneClickv1.7-ShortFuse
Step 3b: If you are successful in ROOTING your phone - SuperUser app will be installed to your Xperia X8
Step 4a: Switch off your Xperia X8 and pull out your SD Card
Step 4b: Format your SD card to FAT32 (I am using stock 2GB) - recommend you use an adapter (I used a SD CARD Adaptor)
Step 5a: Partition SD card into 2 FAT32 partitions (e.g. 1.37GB & 500MB).
Step 5b: Set both partitions to PRIMARY -> [Do not name your partitions]
Note: 1.37GB is now your phone storage and 500MB will be used by Link2SD app - so don't put stuff into that 2nd partition)
Step 6a: Put SD Card back into your Xperia X8 and restart
Step 6b: Connect Xperia X8 to PC - Mount SD Card
Step 7a: Copy your data back into your SD card's biggest partition.
Step 7b: Copy Link2SD v1.5.3 apk to the root of SD card
Note: You can get Link2SD APK from here - [App] Link2SD - xda-developers
Step 7c: UnMount your Phone (SD Card) from your PC
Step 8: Goto Market download Astro File Manager (if you don't have a File Manager)
Step 9: Launch Astro and install Link2SD
Step 10a: Launch Link2SD -> Root access required (SuperUser -> allow access) - within the Link2SD app, select the apps you want to move to SD Card and press <Create Link>
Step 10b: If your select an app that has already been linked -> you can use <Remove Link> to put the app back into your phone's memory.
IMPORTANT THINGS TO NOTE:
1) After you have "MOVED" all your apps to SD Card you MUST to reboot your phone in order to "See" and "Use" the apps again.
2) Apps that cannot be used or get a "Forced Quit" dialogue box will have to be reinstalled and then move again to SD Card using Link2SD app.
3) System apps cannot be moved to SD Card. You can REMOVE them by using Root Explorer app
4) If you want your installed apps to be updated via Market - Launch Link2SD & Hit the <Market Fix> button (ONLY after you have moved your apps to the SD Card and reboot your X8)
5) Use Link2SD to check your storage info - if your use the "Settings" option on your phone, you will not be able to see the 2nd partition's info.
And that's it. Have Fun!!!