Hi,
Kaye England's rulers, called Nifty Notions Rulers - Quilt for a Cure (some of the proceeds go to Breast Cancer Research) - are wonderful for half-square and quarter square triangles. For the half square triangles you put two strips right-sides together, and then use the ruler to cut the triangles, sew on the diagonal, and you are done - no squaring up needed! The ruler allows you to make half-square triangle units from 1 inch to 8 inches. The quasrter square triangle ruler works the same way. In addition, a combination of both rulers will make flying geese - no need for special rulers of varying size! Not all quilt shops carry her rulers, but you may be able to get them from her web site (not sure) - just Google Kaye England. They are wonderful! She also has many other rulers bor bias traingles, kaleidoscope (both can be used to make very easy dresden plate pieces), half-rectangles and many more. And the rulers all have little round holes on the whole-inch lines which are wonderful for lining up your fabric! Give some a try - I think you will love them!