Most of the time, this isn't true. The Cortex A8 was made to run at 600Mhz to greater than 1Ghz, and that's quoting ARM's website. So, if you keep it at or under 1Ghz, you're not gonna hurt the phone since it was made to run at that speed anyway.
They're maemo and MeeGo... "Meamo!" sounds like what Zorro would say to catherine zeta jones... after she slaps him for looking at her dirtily...