Copy images and photos from PC to the iPhone's camera roll

Get Image Transfer by Capable Bits from the App Store in your iPhone. After launching the app click on 'Receive Photos' and enter the IP address on your computer's web browser on which you have the photos you want to transfer and select the photos you want to upload from you PC to your iPhone's camera roll album. Both computer and iPhone should be on the same (WiFi) network.

Find album artwork for your itunes library

Head over to the itunes artwork finder website (while it hasn't been taken down by apple) and get your album cover fix.

Find out the MAC address of a PC on your network

Click start, type cmd and press enter. Type ping and the name or ip address of the networked device of which you want to know the MAC address. Then type arp -a and press enter. Next to the ip address of the networked device will be the MAC address (or physical address).

Connect your iPhone to a VPN server

Go to Settings, VPN, Add VPN Configuration..Choose PPTP. Type in any description and enter the server's IP address or the domain name of the vpn server. Type in the user account name and password for the vpn server and tap save.
Next time you want to connect to the vpn server with your iphone just select the configuration you did earlier and slide the vpn button to the right to initiate the connection.

Log in to to windows 7 automatically with a specific user

Run netplwiz (Win-key, type netplwiz and press enter), select the user you want to load automatically into windows and uncheck 'Users must enter a user name and password to use this computer', click ok and enter the password (or leave it blank if the user hasn't got a password) for the user and confirm, ok. Next time windows starts it will automatically log in with that user's account.

Setup your Windows 7 PC as a VPN host

Make sure that the PC you want to setup as a vpn host has a fixed local ip address and configure your router to open the PPTP (Point-to-Point Tunneling Protocol) port 1723 for the vpn host's ip address. Usually you can open your router's options at http://192.168.1.1/ with your browser and find the port forwarding options under NAT (Network Address Translation) in advanced setup.

Now go to Network and Sharing Center in the windows control panel, click change adapter settings and in the menu click File, New Incoming Connection... and follow the instructions (if you don't see a menu you should enable the menu bar first (Folder options-View-Always show menus)).  Choose user that uses a password, next, through the internet, next, leave the default check boxes and click 'Allow access'.

Get a free dyndns account

If you are using a dlink router you are eligible to one free dynamic dns address. Just go to www.dlinkddns.com, register and create your address (e.g. yourname.dlinkddns.com).You can download and install Dyn Updater to your PC and enter your details that you created at dlinkddns. Now everytime your internet IP address changes it will be updated to your ddns address.