Under SQL Server 2000, I STRONGLY recommend that you use SCOPE_IDENTIY().

Try the following:

CREATE TABLE a (a int IDENTITY(1,2))
CREATE TABLE b (b int IDENTITY(2,2))
GO

CREATE TRIGGER InsertA ON a FOR INSERT
AS
INSERT INTO b DEFAULT VALUES
GO

INSERT INTO a DEFAULT VALUES
SELECT @@IDENTITY
SELECT SCOPE_IDENTITY()

While @@IDENTITY is scoped to the connection, it is not limited to the session. After running the above script, you should see that @@IDENTITY contains a two (2) which was the value inserted into the b table. Probably not what you were expecting.

-Mike