What is this C# pattern for property initialization?

Question

I'll often have objects with properties that use the following pattern:

private decimal? _blah;
private decimal Blah
{
    get
    {
        if (_blah == null)
            _blah = InitBlah();
        return _blah.Value;
    }
}

Is there a name for this method?

Answer 1

Lazy initialisation.

.NET 4, when it arrives, will have a Lazy<T> class built-in.

private readonly Lazy<decimal> _blah = new Lazy<decimal>(() => InitBlah());
public decimal Blah
{
    get { return _blah.Value; }
}

Answer 2

Lazy loading, deferred initialization, etc.

Noet that InitBlah should (in this case) ideally return decimal, not decimal? to avoid the chance that it gets called lots of times because it is legitimately null.