I was thinking about doing the same, but for a variable amount of Bitcoin, ideal for posting prices online, for example 0.1 Bitcoin would generate an image with $5,132, and so on.
Yes, this is a nice idea. However, I don't see that there's, seriously now, a lot of utility in this project. I just made it for fun. Sure, this may be used by some and sure, it isn't that hard to implement. I may make it.
I was also thinking of expressing the addresses' balance in a fiat currency.
The next step I was thinking was to add other currencies, and back and forth conversions.
This could be another feature. I'll probably introduce all of the three mentioned in the next update.