When developing for 2.0+, the supposed way is setting android:inputType="textNoSuggestions"
(ref).
Unfortunately, suggestions are still shown on HTC Desire 2.2 (and probably other HTC Sense devices as well).
Using android:inputType="textVisiblePassword"
will not help as well as the software keyboard by HTC won’t allow you to switch languages.
So I stick to android:inputType="textFilter"
to disable suggestions.