Don't say I didn't tell you so if you happen to be short on a few lens caps and body caps. When that happens, it will make things difficult to pack things back into your bag since you can't remove the lens from the body. After a long shoot this past Sunday, i've realized i'm down to a few spares (again). Luckily for a set of two caps, it's just over $1.00 dollar + Free Shipping. Had to grab a few more sets since they'll take about 2 weeks to come in..
Canon Rear Lens and Canon DSLR Body Caps
For an important list of other inexpensive spare items (including Front Caps with Logos, Hoods, & Pouches), check out this article: http://cheesycam.com/hoods-covers-caps-and-pouches/