Syntax based on ObjectSpaces:

http://www.wilsondotnet.com/Controls/

Largely compatible with the syntax of MS ObjectSpaces in .NET v2.0.
Supports MS Sql and Access -- Oracle, OleDb, and Odbc are untested.
No need to inherit objects from a base class or embed any attributes.
Object-relational mappings are made in an extremely simple xml file.
Includes a Windows ORHelper to generate the mapping and class files.
Can optionally use stored procedures for Insert, Update, and Delete.
Explicitly create objects with new and StartTracking, or use GetObject.
Retrieve individual objects by key (identity, guids, or user-entered).
Retrieve collections as a static ObjectSet or a cursor ObjectReader.
Query with any where and sort clauses, or setup a default sort order.
Supports paged collections -- queries can specify page index and size.
Supports 1-to-many child relationship, with an optional lazy-loading.
Collections support one-way read-only binding for both Web and Windows.
Persist individual objects, or a collection of objects in transaction.
Separate instances can be created for multiple databases or providers.
Easy to deploy with simple x-copy in shared web hosting environments.
Supports server systems with a configurable session and cleanup time.
Performance is now very much comparable, sometimes better, than DataSets.
Objects should implement IObjectHelper to achieve the best performance.
Objects can implement IObjectNotification to handle persistence events.
Free to demo in VS.NET debugger, purchase of $50 includes C# source.

Update: WilsonORMapper v1.1.0.0 (1/27/2004) includes the following features:
(1) Now supports One-To-Many, Many-To-One, and Many-To-Many relationships.
(2) All relationships support lazy-loading, use ObjectHolder for Many-To-One.
(3) Stored Procedures with parameters can now be used to load collections.
(4) GetDataSet allows you to specify what subset of columns to actually load.
(5) Execute set based updates and deletes, including expressions with updates.
(6) Oracle support has been tested, and a provider model has been introduced.
(7) ORHelper: Chad Humphries has made some improvements to the logic and GUI