To get my licentiate degree (it's kind of Polish bachelor degree) I wrote a thesis on transferring contacts and calendars between mobile devices and, in addition, to make an example, this app. I hope you'll find it useful in backing up your precious data or copying it to another phone.
Go to downloads and get latest files. JAR file is essential to install the program, while JAD only speeds up the instalation on some phones.
MobileTransfer should work on any phone supporting Java ME with special package: JSR-75 (available on most devices after 2004). Majority of supported phones is listed in J2ME Polish device database.
App is tested and works fine on S40 (eg. 6230i, 5300) and S60 (eg. N82, N73) Nokia phones, Sony-Ericsson (eg. K610i, C902), some touch-screen LG (GT500 for some reason couldn't see backup folder at first, later it was OK) and Samsung.
Install app through PC or directly on the phone. Some devices (eg. Nokia phones with s40 system) requires granting write privileges. To do so go to applications options, select 'Application access' => 'Phone access' => 'Add and edit data' and set it to 'Ask every time' (if possible choose 'Ask first time only' or 'Always allowed'). This process may vary depending on the devices system. Sometimes those settings can be found in 'Application manager'.
The main menu of Mobile transfer has four items.

creates a backup of contacts, calendars events and to-do's. The data is stored in one *.txt file (Backup-YearMonthDay.txt) using vCard and vCalendar formats.
restores previously done backup. Note that it does not change or update data on device but add all backed up items as new contacts/events/to do/etc. If no file is found an alert pop-ups.
If you created backup with Polish version and wont to restore it in English version look at this site: Backup file.
allows you to choose a path where the backup file is or will be stored.

App is designed to show firstly a gallery folder and then all available for JavaME paths.
On most devices:
- first available path will lead to gallery folder, which is also a default path (this is because of access restrictions which, on some devices, didn't allow app to save data in other locations),
- second path points at phone memory (second and third path in above N82 screenshot),
- third path is a memory card (if available in phone; fourth and fifth path in screenshot).
Choosing a proper path is especially important before starting a restore process.
This screen contains short help and button 'Check' which is checking devices compatibility.
Unfortunately you'll have to get used to answering applications access prompts, other ways device won't allow app to read or write any data. Trusted certificate that would reduce these prompts to one or two costs about 200$ so... ;]
Data is sorted by PIM lists types (eg. Contacts, Contacts SIM, Calendar events, Calendar anniversaries, etc.). It's possible to edit the file unless stamps (eg. 'Contacts - list: Contacts' or 'Contacts END') wont be changed and changes to items will be done according to vCard or vCalendar format.
Simple backup file:
Contacts- list: Contacts
BEGIN:VCARD
VERSION:3.0
BDAY:2007-01-17
FN:Test Name
REV:20070117T020000
UID:com.sun.j2me.pim.PIMProxy$Item@e5125d64
END:VCARD
BEGIN:VCARD
VERSION:3.0
FN:Temp Name 1
REV:20061023T020000
UID:1.vcf
CATEGORY:test
END:VCARD
Contacts END
Calendar - list: Events
BEGIN:VCALENDAR
VERSION:1.0
BEGIN:VEVENT
LAST-MODIFIED:20040602T054727
SUMMARY:test
UID:com.sun.j2me.pim.PIMProxy$Item@15dc1cbe
CATEGORIES:test
END:VEVENT
END:VCALENDAR
Events END
Calendar - list: Anniversaries
BEGIN:VCALENDAR
VERSION:1.0
BEGIN:VEVENT
LAST-MODIFIED:20030602T054727
SUMMARY:test1
UID:com.sun.j2me.pim.PIMProxy$Item@13b2f0f1
CATEGORIES:test
END:VEVENT
END:VCALENDAR
Anniversaries END
To-Do - list: To Do
BEGIN:VCALENDAR
VERSION:1.0
BEGIN:VTODO
LAST-MODIFIED:20040602T054754
SUMMARY:test
UID:com.sun.j2me.pim.PIMProxy$Item@3d51ca8
CATEGORIES:test
END:VTODO
END:VCALENDAR
To Do END
Yeap, it works, look, I just restored almost 300 contacts, 114 calendar events... ;)

Anonymous