Problem Description:

You have a Sony Ericsson phone that can play MP3. For example, the Z1010 . It plays mp3s fine, but the song names are corrupted because they're in Hebrew! (Or any other language that the phone can show but is not English).
You want to be able to see the ID3 info in your own language correctly.

Requirements:

The Solution requires that:

Your Sony Ericsson will support your language (here, Hebrew). You can be sure it does if you can see SMSes in your language (even if your menus aren't in this language and you can't even write in it).
You'll have iTunes (you can download from Apple).
Somewhere you can see the ID3 tags correctly (Your PC or any other machine).

The Solution

First, get the MP3s into a new iTunes playlist. It can be directly from the Memory Stick if you have a USB reader, or by transferring it from the phone to your computer.
Then, edit all ID3 tags to show up correctly. Hebrew ID3 tags will not show up correctly, but as gibberish of some sort. Surely it's their encoding but I haven't tested enough applications that can edit id3 tags and save text in unicode. I had to re-type all ID3 tags so they will show up correctly.
While editing ID3 tags note the Previous and Next buttons on iTunes. This makes it much easier to edit those tags.
After your playlist shows the songs info correctly, right-click (or hold CTRL if you're on a Mac) and select "Convert ID3 tag.." and convert it to ID3 tag version 2.3.
Upload the files back to your phone, or just exit iTunes if they're stored on the card.

That's it! you're done!
If you've followed the instructions carefully you will now see the correct song names in the phone.