I have decided to take on yet another piece of IT torture: get an IPSEC VPN working on my 808 phone 
The other two - PPTP and SSL - are generally easier to get working, especially PPTP. But there is no adequate client support for these on Symbian.
If I can get it to work, I will be able to browse remote PCs, with file transfer, which is occassionally very useful.
So far, 2 days later, no luck...
The only previous occassion on which I was able to get IPSEC working was a site-site VPN between two Draytek routers, and only by precisely following their application note. With a laptop client, never got anything working.
I know enough about them to suggest you waste your time on something else...
Still - drop me an email if you have any specific issues, I might be able to help. I use the same thing on iOS (even there it was painful).
Setting up IPSEC on your own on both ends is the equivalent of doing a JAR IR but haven't you just done that?
PPTP is much easier. Google shows hits for PPTP and Symbian.
There is just one PPTP client and the developer has stopped selling it. It uses some weird license management scheme which nobody has bothered hacking yet. So that option is out, it seems.
IPSEC is not hard to set up. On the 808, you install a Nokia VPN app. That has no user interface. To config it, you use an app on the PC which interfaces via USB or bluetooth. In there you can set up all kinds of stuff in the phone, using a nice GUI. And all this actually works.
Nokia supply .vpn files (preconfigured configs) for popular high-end corporate routers - much as Apple do for IOS, for Cisco models etc. But in my case I am using Draytek routers; not cheap ones, and they work well.
Unfortunately it doesn't work, due to some subtle issue. IPSEC has about 30 parameters which can be potentially configured, and if any one of these is incompatible with the VPN terminating server, you've had it...
PPTP is much simpler, but only because Windows comes with a PPTP client and everybody who makes a VPN router that supports PPTP will test it with that. Unfortunately PPTP is not a purely-TCP/IP protocol and requires specific network support, and not all networks support it. Often, PPTP does not work in public WIFI networks, or 3G networks.
SSL is the most universally functional because it uses Port 443 (HTTPS) and everybody has to support that. Its weakness is a lack of clients, especially ones that provide a network connection. Windows doesn't have such a client; one has to use 3rd party ones. And you can't run an SSL VPN to a server which already runs an HTTPS website of some sort, on the same IP, apparently.
IPSEC can be made to work if enough expertise is chucked at it... which happens in large corporate deployments.
we have that expertise if you need
It was a few years since I configured VPNs, but hopefully I can assist you if you haven't figured it out yet, just drop me an email :)
Martin (and others), thank you
Currently, I am trying to establish with Draytek, by looking at router logs, if there is any indication the phone is even reaching the router.
They seem to have a quota of 1-2 email replies per 24hrs and absolutely no phone option, which makes it a slow process
If the phone is not even transmitting, then the problem is rather more basic. Symbian is quite powerful in the way it enables different apps to use different "access points". In normal "smartphone" operation this runs smoothly, by accessing one called "Internet" (which in turn is a prioritised list of any mixture of wifi or 3G channels, and this is quite slick for situations where you deliberately want one and not the other) but there are clearly means whereby the VPN can be trying to get out some other way.
