I need to send invoices, as a part of my job. I use to write them on my own, but I wanted a better way to write them and keep track of my outgoing invoices. I happened to stumble upon Blinksale. It appears to be a nice web app for creating and sending and keeping track of all of your invoices. There is a free basic version, so you should give it a try. I have only used it once and so far have been happy with it. I’ll let you know what I think after I have gotten the chance to use it a little more.