So I was using Unison and queued up a little under 1000 images to download. Shortly thereafter memory usage for Unison approaches 600 MBs of real RAM. My swap directory balloons to 2.4 GB of disk space used.

[them:them:/Volumes/Downloads:2:25am:2025] -> du -sh /var/vm
2.4G /var/vm

Soon after that my computer becomes unresponsive and an error window pops open telling me I have run out of disk space for application memory. Thank you Panic for making a news reader break OS X.

Now I'll sit and have a jumpy mouse cursor for an hour while expired page files are deleted.