GCalSync is an app that offers two-way synchronisation between your mobile/cell phone or Blackberry and Google Calendar.

You can download events from GCal to your mobile phone and upload events created on your mobile, although at the moment, changes made to events on your mobile are not synced.

The past and future date ranges are user-customisable.

Currently the app does not support reminders and treats repeating events as multiple single events, but the developer promises more features soon.

Lots of Nokia handsets are supported as well as many Sony Ericsson models and two Motorola phones (not my RAZR, however, hence no screenshots).

You can read more about it and download the app on the developer’s web site or just point your phone at http://wap.gcalsync.com to get started.Google calendar, cell phone, mobile phone, blackberry, syncing, nokia, productivity

Om Malik provides a walkthrough for syncing iCal and Address Book with Yahoo!’s web-based PIM service, Yahoo! Go.

You can do this using one of the nine Nokia cell/mobile phones compatible with the service—N70, 6680, 6681, 6630, 6600, 7610, 6670, 6682, 6620.

The Yahoo! Go Mobile service is designed to allow anyone with a Yahoo! account to get the content (including email) of their MyYahoo portal page on their mobiles.Yahoo! Go, MyYahoo, email, Nokia