Regular readers of Daring Fireball know John Gruber has an almost unhealthy fascination with the Helvetica font, but sometimes fanaticism pays positive results. Today he posted a hack to make the iPhone Notes application use Helvetica rather than the much despised Marker Felt font. The hack involves actually modifying the MobileNotes.app binary with a hex editor on your Mac and is thus probably not for the faint of heart. Needless to say you'll also need to have already hacked the iPhone enough to get access to the MobileNotes.app binary in the first place, but if you just can't stand Marker Felt here's a way to fix it. Gruber also warns, however, that there's no telling how long this hack will work, particularly with the forthcoming firmware update.