I made a set of mini alphabet cards, laminated them and stuck a magnet on the back, and we have been using them for doing the worksheets I made to go with Sonlight Language Arts 1. We also use them for spelling and other activities.
In her book Sue mentiones "Paying close attention to the number of skills that will be necessary to complete the work" (pg 82). I have a child who hates to write so for her using the magnetics is focusing on the words and not on the extra skill of writing. It makes this activity achievable for her.
So far I only have the lowercase alphabet done. I need to get another box to put the uppercase letters in.
You can download the mini alphabet here if you want some too.