Hi Ray
I don't use Google Chrome but I think that you can use tab browsing ( I use tabbed browsing on Firefox and it works well )
Open Google Chrome, go to the Practical Caravan Forum and log in as normal.
When you have done this, stay on the forum page which shows the message board index ( titles of threads in different sections and latest posts etc)
Left Click on the yellow Practical Caravan logo and keep the left click pressed down.
'Drag' the logo, (which will show up as a small dotted line rectangle) to the Google Chrome task-bar (blue at the top of the Chrome page)
Release the left click and if Chrome works in a similar way to Firefox a second tab will appear with Practical Caravan on it. Unless you choose to discard the new tab it should appear every time with you logged in. You might have to refresh the original forum page to bring it up to date, although I never have to do this with Firefox logged in to the website home page.
If you need any further help give me a shout via email