I really can't think of one thing that has required me to use cash (instead of a check or credit card) in a long long time. (ok, buying used stuff off craigslist)
Ok, in that instance, I just put down my $100 as an expense for whatever, and a $100 credit in Paid In Capital.
I can then pay myself back the Paid In Capital because I didn't use business money to do it originally.
but seriously, you shouldn't use cash for 90% of this stuff. Just throw it on the business credit card.