According to this Reuter’s report, Three is to offer its customers access to their existing MSN Hotmail and Messenger accounts on their handsets. Users simply login with their existing account details.

The slickest implementation I’ve seen of this to-date is by OZ Communications, a Canadian company with a particularly strong focus on user experience. It’s not clear whether Three is using the OZ platform, but they are already running services for Cingular, Sprint, Bouygues and Telefonica, among others.

All of the major IM and email providers are busy inking deals to expand their services to mobile. One of the biggest challenges is providing a consistent experience across handsets. The typical approach is to target high-end devices with dedicated client software and provide a simplified, browser-based version for other models.

This is an area where Google, in particular, looks set to struggle if it tries to maintain its browser-based approach. While the AJAX (Asynchronous JavaScript and XML) technology on which many of Google’s new services is built is starting to appear on mobile devices (e.g. Opera’s browser – http://www.opera.com/products/mobile/platform/), it is far from pervasive. It will take years for it to reach mass-market penetration levels. To deliver a consistent experience, Google is faced with the choice of adopting a different, more client-focused strategy or waiting for market conditions to evolve.

Initiatives are underway within the operator community to develop a single standard for mobile instant messaging. However, this only addresses part of the problem, primarily at the server level and leaves the client experience as a considerable challenge.