I'm curious from a "how good is Lisp long term" angle.
That's what I was talking about at the time when I described it somewhere as a new world record for Greenspun's tenth rule.
(full nsfw image). Check out the strategic, crude touch up designed to keep away obscenity charges.
(It's called default because it used to be the placeholder photo on my website for people who hadn't uploaded a profile pic. I don't know who originally took it, or how to ask them for permission to use it, so I replaced it with something else. I keep it around because it's really funny though)
Fatal error: Allowed memory size of 94371840 bytes exhausted (tried to allocate 64000000 bytes) in /home/kingkool68/dummyimage.com/code.php on line 18
Curiously http://dummyimage.com/8000000x1 works
And should have option to set RGB of image.
If this is simply for formatting placeholders while designing web pages, wouldn't <span style="width: xxx; height: yyy; background-color: grey; border: 1px solid black;"></span> be a pretty easy workaround, and a lot easier on the network bandwidth?
The more important point to my mind is that grey is definitely not lorem-ipsum. It doesn't help me evaluate anything except image size. And since it's easy to get a sized placeholder, a server to generate a URL seems not that helpful.
Just make sure you don't use 'system()' (or the equivalent call in whatever your language is) to launch things. It was a bad idea from the start.
My normal advice to you nifty niche App'ers is to look at long standing apps to see what they did right for revenue. Namely http://www.network-science.de/ascii/
 GD still has its own problems, but it seems like subscribing to secunia for GD would catch most, like this recent one :: http://secunia.com/advisories/38055/
Some features that would make this really useful:
- custom colors (as mentioned by others)
- an X across the image, corner to corner
- Optional text instead of the size (i.e. "lead photo", "thumb")
- a tag (or the resolution) repeated in an offset "brick" pattern across the entire image, similar color to BG
The last one probably overkill but useful for when you are doing something like scrolling window, where not all of the image is displayed.
I've now gemified it for use in Rails apps without having to hit a separate site. It emits data URIs at the moment only, so no IE love yet. I had immediate need for it.
I believe that dummyimage thing is dead simple.
Planned additions include
True file format support (add .jpg and you get a real jpg etc) Right now you can add an extension but it still serves up a gif.
Easier syntax for making squares (/250 would work instead of typing /250x250)
Ability to change the background color
Warning: imagecreate() [function.imagecreate]: Invalid image dimensions in /home/kingkool68/dummyimage.com/code.php
That taught me to process my financial side-effects with explicit, visible, calls; the generic dispatch, and abusing behind the scene meta-object features will make you broke.