We've just started offering our custom cryptocurrency and math based posters on https://bitographs.com. Each poster is composed of text as returned by the getblock API call that can be customized to start from a block of your choice. Commemorate that moment in Bitcoin history with the text describing the block in which it happened -- forming a nice looking, unique poster that also holds useful information!

We accept Bitcoin and a variety of altcoins as well as Credit/Debit cards, and we donate 5% of all sales to https://www.changetip.com/tipme/changecup which goes to help feed the homeless in NYC.