Here are some online tools I've been using with a lot of satisfaction. Of course, your mileage may vary:
Feedblitz is a reliable, handmade alternative to Feedburner and other corporate solutions. They handle the email and RSS feeds to this blog, and Phil is just a pleasure to work with.
Ziggeo is the tool I used to preview thousands of applications for my summer internship. Used correctly, this is an extraordinary way to get insight on a large number of people in a very short period of time. I could see it being a great screening device for anyone running ads on Craigslist, for example.
Typepad hosts this blog, and always has. People ask me why I don't switch, and my simple answer: it's not broken. I like having a service I can pay for, because when you buy something, you're the customer, not the product.
duckduckgo.com is a smart, fast, private search engine with a silly name. What more could you hope for in a search engine?
compfight is a secret weapon in the search for useful cc-licensed photos. Don't forget to donate if you use it.
Eventbrite is a surprisingly robust and reliable way to sell tickets. I use it for seminars, but there's a whole host of ways you could use it to sell slices of a limited digital resource.
If you like reading blogs, you really should consider reading them via RSS, which is still the most efficient way to do it.