If you are truly stuck for an anagram when playing Scrabble, there are some great sites which offer you suggestions. The most effective of these seems to be http://www.wordseeker.net/ as you can choose which dictionary to use, such as SOWPODS or TWL and it gives you more valid words than the other sites I have tried. Does it seem like cheating? Well, my own take on this is that I work really hard to think of a suitable word when it is my turn, then play the word. Afterwards, I sometimes check up to see what I could have played. For example, today (see image) I had the bingo SLANTER ready to put down but was blocked by my opponent. I was going to put it next to PATE to make SPATE, but he played MOGS. Afterwards I was able to see that I could also have tried ANTLERS, RENTALS, SALTERN and STERNAL. In this case, none of them would have fitted, but maybe I'll remember some of the other words for next time.
Tips for playing Scrabble using the SOWPODS English and American dictionaries