I too wrote a slightly different version...  Same binary concept, implemented slightly differently with a twist!  It allows the specification of an increment or step value.

CREATE FUNCTION dbo.udf_genDateSequence
   (
      @prmLoDate datetime, -- lower date boundary (starting value)
      @prmHiDate datetime, -- upper date boundary (maximum value)
      @prmIncDays int      -- increment value
   )
RETURNS @Dates TABLE (DateVal datetime NOT NULL PRIMARY KEY)
AS
/*
Function:   Generate a table of dates.
Strategy:   Set-based scalar value generation.
Usage:      dbo.udf_genDateSequence(fromValue, toValue, stepValue)
*/
BEGIN
   DECLARE
      @daysDiff int,
      @swapVar datetime 
 
   IF @prmLoDate > @prmHiDate
         BEGIN
            SET @swapVar = @prmLoDate
            SET @prmLoDate = DATEADD(day, DATEDIFF(day, 0, @prmHiDate), 0)
            SET @prmHiDate = DATEADD(day, DATEDIFF(day, 0, @swapVar), 0)
         END
      ELSE
         BEGIN
            SET @prmLoDate = DATEADD(day, DATEDIFF(day, 0, @prmLoDate), 0)
            SET @prmHiDate = DATEADD(day, DATEDIFF(day, 0, @prmHiDate), 0)
         END
 
   SET @daysDiff = DATEDIFF(day, @prmLoDate, @prmHiDate)
 
   INSERT INTO @Dates VALUES(@prmLoDate)
 
   WHILE @prmIncDays <= @daysDiff
      BEGIN
         INSERT INTO @Dates
            SELECT DATEADD(day, @prmIncDays, DateVal)
               FROM @Dates
               WHERE DateVal <= DATEADD(day, -@prmIncDays, @prmHiDate)
 
         SET @prmIncDays = @prmIncDays * 2
      END
   RETURN
END
go