I got an Android phone a while back (a Samsung Intercept). I like it a lot, except it started getting slower and slower and slower.
After yelling at my phone profusely and spending an hour or so Googling, I discovered that a process called akmd2 was the culprit.
This process is what automatically switches the screen from portrait to landscape mode when you rotate the phone. Seeing as I actually hate that feature, I solved my problem by disabling it:
That is it! My phone is now instantly super fast!
My phone has a slide out keyboard, so I can still get my screen to rotate by opening the keyboard.
Anyways, I hope this helps someone that runs into the same problem.