I'm working on a couple of iOS apps that require the user to select a calendar date, and while the built-in date picker widget is all right, I'd much prefer if users could choose days from a calendar grid, similar to how it works in Hipmunk's iOS app. In that app, users are shown an infinite scroll view showing a grid of days, with each cell showing the month and day. The days of the week are shown in a persistent (i.e. non-scrolling) banner.
In addition to simply showing a calendar, this control should allow dates to be highlighted/selected. Better still, users should be able to select a whole range of dates by tapping on the start and end days' cells, at which the whole range of days should be highlighted.
Any ideas?