Is there a product that will let me send a print job to a shared printer from anywhere on the Internet? I know there are remote solutions for networked printers; however, mine is a cheap laser shared to my local LAN.
Google just recently released an option for "cloud" printing. This mean that if you use google chrome you can print from anywhere to a PC that is connected to your printer (provided that PC is always on and connected).
Google has put together an easy to follow, step by step process on setting up Google cloud printing here:
You could try www.printnode.com. You have to install a piece of software on a computer which is attached to the printer. Once that is done - you can print by sending a printjob as an email attachment, by uploading a .pdf file to the website or using the JSON API.
I've only used it once or twice and it seems reasonable reliable. You get 10 free prints when you sign up but then you have to pay but frankly it isn't very expensive.
I prefer this over the Google Cloud printing service because you don't need to have Google Chrome installed all the time.
If you are taking your own laptop/computing device around with you, you can do this through a VPN connection if you setup OpenVPN at both ends.
There's a useful howto here: http://www.runpcrun.com/howtoopenvpn
You could also use the Internet Printing Protocol (IPP) with some versions/mixes of Windows - Microsoft has a primer/howto/more info here:
Microsoft has made it harder to support IPP services on Vista and Windows 7, so a better option may be a print server that supports IPP - for example, the D-Link DPR-1020:
...or there's IPP support in Linux if you want to bring that into the equation: