MOSS 2007 comes with a number of filter web parts that makes it really easy to filter your SharePoint lists by connecting filter web parts with list view web parts. Out of the box, there are 10 filter web parts available.
There's one new filter web part in particular I find very powerful, the Current User Filter. With the Current User Filter you can filter the contents of web parts by using any property of the current user.
As an example of its use, imagine you build a corporate asset register based on a custom list. One of the columns, 'Asset Location', records which office the asset is located at. You also create a number of views to ease the management of the asset register (e.g. group by asset type, sort by purchase date, etc.).
For each local office, you nominate a person to look after the asset register for the local office. That person is only ever going to be concerned with the assets in the local office, so to make life easier for that person, you want to hide asset records from other offices.
Providing that the users have their Office property set in their user profile (imported from AD), you can use the Current User Filter web part to filter the asset register. Because all list views in SharePoint 2007 are proper web part pages, you can add the Current User Filter to all the views you have created for the asset register.
In the web part properties for the Current User Filter you can specify which user profile property to use (in this case 'Office'). You then simply connect the two web parts by sending the filter value from the Current User Filter to the appropriate column (in this case 'Asset Location') in the list view web part.
What you end up with is a central corporate asset register easing aggregated reporting. However, for the local asset manager at each office, it appears to be a local asset register only showing local assets.
Considering you can define your own user profile properties, there are unlimited opportunities for personalising list views. And because all list views now are web part pages, you can extend that personalisation to all the views of a list.