I have been using my DD-WRT Router to access my Home Network remotely over the past couple of years using PPTP. I use this mostly when abroad to get a UK IP address and occasionally to access files from OMV.
I have found the DD-WRT Router slightly flakey in relation to VPN access over PPTP. I even upgraded to a Buffalo Router that came with DD-WRT from the factory but it still was not a reliable solution. I have messed around with OpenVPN which did seem to work better but I am not happy about having the software on my Corporate Laptop...
Anyway, this brought me to investigate the possibility of using my OMV for remote access. Again, OpenVPN seems the option of choice, but for the reason above and the fact it now looks like the Plugin is not currently maintained I had a poke around to investigate getting PPTP to work.
To my amazement and with my tiny bit of Linux knowledge, it took me literally 5 minutes in the CLI over SSH to get PPTP remote access. I am very happy to say the least. I have tested the connection when out and about using my 3G connection on my iPhone and not had one failed connection yet. My Laptop also connects perfectly and I have not had to install any messy software, just a simple Windows VPN connection. Obviously you need to open up the Port on your Router and use some sort of Free DNS tracker, but I can now browse the Internet hidden behind my Home IP Address and access all my PC's, Routers and OMV.
Although a nice flash Plugin would be nice, I am amazed what can be achieved with a bit of googling.....