(Click here to learn why you should care about, of all things, sinkholes.) [1]
In:
Mobile, Alabama [2]
Somerset, Pennslyavnia [3] - hole opens up beneath a children's soccer field.
Snomomish County, Washington. [4] This one opened up after an Election Day flood. It's been a headache ever since. The county hasn't been able to afford to fix the problem permanently. Maybe they voted for too many conservatives.
Links:
[1] http://commonsense.ourfuture.org/sinking_feeling_thebigcon
[2] http://www.wkrg.com/servlet/Satellite?pagename=WKRG/MGArticle/KRG_BasicArticle&c=MGArticle&cid=1173350912565&path=!news!local
[3] http://www.dailyamerican.com/articles/2007/04/24/news/news943.txt
[4] http://www.heraldnet.com/stories/07/04/24/100loc_a1sinkhole001.cfm