Sid is right.
Take the object you want to rotate (I'll be using the BLIC logo) and copy the layer
Use scale to make the new layer smaller, a little bit off the left and a little bit off the right.
Take this new layer and copy that. Then do the same again, making it a little bit smaller.
Repeat the process over and over until you end up with something very thin. I find it helps to hide all of the older layers it can become very cluttered.
Make the first frame the original layer then one frame for each layer you made in sequence. Here I havent done that, I have simply made frames going back up to the original layer.
ie
layer 1
layer 1 copy
layer 1 copy 2
layer 1 copy 3
layer 1 copy 4
layer 1 copy 5
layer 1 copy 6
layer 1 copy 7
layer 1 copy 8
layer 1 copy 7
layer 1 copy 6
layer 1 copy 5
layer 1 copy 4
layer 1 copy 3
layer 1 copy 2
layer 1 copy
If you've managed to follow this you should end up with something like this.
(Remember you must use "save optimized as" not "save as")
If you want complete rotation, you need a lot more frames.
To make it easier I renamed all the layers in order.
Then I made copy's of each layer
Each of the copied layers is then horizontally flipped
Then comes making the frames, for full rotation of this image the sequence is as follows
Layer 1
Layer 2
Layer 3
Layer 4
Layer 5
Layer 6
Layer 7
Layer 8
Layer 9
Layer 9 copy
Layer 8 copy
Layer 7 copy
Layer 6 copy
Layer 5 copy
Layer 4 copy
Layer 3 copy
Layer 2 copy
Layer 1 copy (Now the image is rotated halfway around so you now need to reverse the layer sequence, so....)
Layer 2 copy
Layer 3 copy
Layer 4 copy
Layer 5 copy
Layer 6 copy
Layer 7 copy
Layer 8 copy
Layer 9 copy
Layer 9
Layer 8
Layer 7
Layer 6
Layer 5
Layer 4
Layer 3
Layer 2
This gives you full rotation