it depends on the situation. if you're shilling for a co. and choose not to disclose it, then you're lame. if you're hired to blog, it's ok

and disclose it...obviously.

considered paid blogging ... worries that the insertion of paid posts with reduce cred of his non-paid posts with/without disclosure

PlurkingPoppa, location is a good point. onmy personal blog, i'd take ads, but not payment for content

I like the sound of being slightly detached that way.