This is a very simple style that does just one thing - it makes the search field for creating impromptu dynamic lists (smartlists) much longer than it is by default. I've set the width to about the maximum it can be on the normal RTM screen - 750 pixels, however, if you are using one of the other RTM scripts here, specifically the excellent Remember The Milk widely scripts, you can push this out much further - I have mine set to around 1000 pixels for example.

*** note - RTM creates a confirmation note of sorts after you do something (change or delete something in RTM) to the right of their logo. In order to avoid the search box obscuring this note, I pushed the search box down a bit. This will only account for 1-line confirmation notes, though, although that should be 90+% of the ones you encounter. ***