Solution for Skype cannot connect, only the blue connection progress indicator is spinning

If you have net connection and other apps like the browser work then try signing out completely from skype and sign in again.

Exlamaction mark next to wifi icon on android

It indicates the phone cannot connect google servers. A reboot usually solves this if the problem persists.

The reason why PHP Can't connect to MySQL server on 'localhost'

If you can access the server from the command line with a mysql command issued without parameters then there is a good chance the server is configured to use a local socket or pipe on windows, so you need to specify this socket when connecting.

On Windows it's as simple as this: mysql_connect(".")