Share your experience!
Last my sony W580i, it has a birthday field in each contact and it can remain on that day. Now in X10, I can't find the BD remainder. So, how can I record and set the remainder? 
I don't think you can on the standard phone book. I assume you'd have to put the dates in on your calendar separately.
I have my calendar/contacts synced with google and you can set up a birth date on your contact list on google and then add Contacts Birthdays to your calendar which will then appear on your phone.
I also use Jorte calendar rather than the stock one because I prefer the look of it.
What means Jorte calendar? Where can I get it? I dun have Birth date on google account. It's only on may last SE phone. 
I believe you can look it up in the Market.
I had to put the birthdays in manually on to my google contacts online. Jorte is a calendar app but I don't know if will be available to you from getjar or SlideMe application stores as I remember that you can't get on to Android market. If you are happy with the stock application it runs fine, I just wasn't keen on the appearance.
You can't get that there? Oops.
Suze, you seem to like customising your X10's looks! lol