How do you render your game engine text?

Hi

How do most people render fonts in their engines?  For a while now I've been rendering a quad containing the entire text and passing a constant float buffer containing the letter lookups in a long 1536 x 16 texture but I seem to see a few other people rendering a letter at a time in character-sized quads.  My thought is that for a whole line of something like debug info (or in-game info), you're increasing your draw calls by the number of characters even though the geometry is simple and probably locking/unlocking vertex buffers and changing …