Luke,
How about a solar fan? I also didn't want to do a battery and wiring for just a few lights - lanterns work fine, but I really wanted a fan for hot evenings. Some very obliging forum members showed me this site in another post:
http://www.talcoelectronics.com/productdetail.asp?id=70400
and product info
http://www.icpsolar.com/4105/news_details.asp?news_id=8
The solar fan charges two AA batteries so can run for 48 hrs without sunlight. It is meant for boats, so it sounds easy to seal. It is a bit expensive for my budget ($115 on the above site, $150 elsewhere) but it saves me from having to learn how to wire my TD and carry around a large battery so it is worth it to me. We will eventually add a small solar panel for recharging lantern and camera batteries.
Katie