From time to time I am also in a situation where I don't have handy any capture tools. I have found that learning a simple memory trick helps. There are many simple ways to remember a list of ten things. The one I use most is to mentally go around a room I know well, and associate my to-do item with something in the room. Later, I go around the room in my imagination and can recall the items.
I have to make a silly / crazy picture to associate each to-do to each item in the room. For example, "call Mike to ask about car mechanic" linked to the end table is a picture of Mike standing on one foot on top of the small end table, balancing and almost falling. Mike (not a mechanic) is wearing mechanic overalls and holding a big wrench.
Later, I remember end table - Mike - mechanic and it is enough for me to write down the whole idea.
I don't remember exactly where I learned this trick, but here is a link to get you started http://www.buildyourmemory.com/roman.php.