Duptrope Digest is a free online tool for fiction writers to keep track of their submissions.
http://www.duotrope.com/Basically what duotrope does is provide a search function for magazines that publish fiction where you can search by genre, word count and pay scale for a magazine that fits what you want to submit. Then, when you submit, you can track your submission. You can easily see when a magazine is late in getting back to you, when they've closed for submissions and what their acceptance rate is.
Here's what they say about escape pod, just as an example:
http://www.duotrope.com/market_205.aspxI use it to track my submissions, find markets for my stories and just explore what the market looks like. However, not only is it good at helping me stay organized, but it keeps track of the statistic from other writers, so you can see what the average response time is, how often Duotrope writers have been accepted, etc. It's totally free and it's been very helpful to me in keeping track of what stories are out, what need to go out, and who published what.