I've just started to use GPG and created a public key. It is kind of pointless if no-one knows about it. How should I distribute it? Should I post it on my profile on Facebook and LinkedIn? How about my blog? What are the risks?
Best way to distribute your key is by using one of the key servers that are available, such as keyserver.ubuntu.com, pgp.mit.edu or keyserver.pgp.com.

If you use Seahorse (default key manager under Ubuntu), it automatically syncs your keys to one of these servers. Users can then look up your key using your email address or keyid. 

If you wanted to post your public key on LinkedIn or your blog, you can either upload the key to your server or just link to the page for your key on one of the keyservers above. Personally, I would upload it to one of the keyservers and link to it, as it is easier to keep it up-to-date in one place, instead of having the file in loads of different locations. You could also share your keyid with people, and they can then receive your key using gpg --recv-keys.

If you wanted to post your public key on Facebook, there is a field to place it under the Contact Info section of your profile. You can also change your Facebook security settings to use this same public key to encrypt their emails to you.

For example, here's my public key. 

To my knowledge, there are no risks associated with publishing your public key.
