SurveyMonkey and web apps for meeting setup

I've seen this site used with quick group questions such as dates, places, etc.

SurveyMonkey.com:

... SurveyMonkey has a single purpose: to enable anyone to create professional online surveys quickly and easily...

In a similar vein are a number of products for setting up meeting times and spots ...

• TimeToMeet: visual calendar sync
• Doodle: this one's quite popular for quick scheduling. Probably next one I'll try. Apparently works without sign-up (smart). No OpenID!
• Tungle: Read-write-web really liked it, I need to study it more. No OpenID! Can work with Google Calendar, but does it require a Google pw (kiss of death).
• TimeBridge: Has iPhone client
• When is Good: No sign up at all.

Ok, so why don't any of these support OpenID?