I have hired Logonerds on multiple occasions and have always been well satisfied with their results. I have contracted them for clients as well as for my own use.
Professional logo design starts at just $27 and offers you a choice of 3 concepts. For more choice and greater flexibility of usage, an upgraded package is still super-reasonable–just $47.
They do a great job, but it doesn’t come together magically… As with most things: garbage in, garbage out. You’ve got to do a bit of direction on the intake form to steer them toward what you’re looking for or results will not be as good. That being said, they are pretty darn perceptive and very willing to do reworks.
If you want help with this process, I offer it as a package. Pricing starts at $150 and includes the fee to Logonerds, but adds my creative input and/or art direction to the mix.
Here are a few examples of logos they have done for me. They can also create custom Facebook headers, Twitter backgrounds, flyers and event web sites, though I have not used them for those services so cannot recommend for that.