For those times when you just can't find the words, here are a few places where the words are given to you. You just have to put them together.
The best of magnetic poetry, but without having to get up and walk to the fridge:
Poetry in Motion: Nice because it limits you to 20 words, which is great discipline for the serious poet. (A caution, the poetry.com folks who host this one have gotten some mixed reviews on their approach to poetry and poets, so wander with care, or just stick to the Poetry in Motion daily challenge, which is what I do.)
Shadow Poetry: I've not played with this one yet, but it looks very similar to the previous, only no word limit and all sales tactics on associated site seem pretty blatant so avoidable.
For either of these, if you end up stringing together something that looks like brilliance, be sure you take a moment to write it down before you close the magnet thingie down. Otherwise, you lose your work. I've lost a few that way.