Feats related to sleeping in armor...

[frankthedm]

Rest in Rust: You may sleep in any armor without suffering the ill affects normally associated with such act. Hygiene concerns still apply.

 

[Kae'Yoss]

My druid (going for master of many forms, he's level 5 and has all the bases covered, so next level will be momf) has the feat. Though I took it because the PrC needs it, I found it useful. The druid wears dragonhide breastplate and is usually the only one with half-decent AC when we're attacked at night (which is not at all rare)