Probably the same you should have to drive to the next bar...
ID card/passport, driving licence/ papers for bike and insurance. Visa/maestro or smth like this

I'm planning a very similar route for 2009, so this thread has been v.useful. Thanks.

Slight differences I'm planning are to go from Poland through Kaliningrad and up to Riga. Has any got any info on Kaliningrad? Visa's etc?

From Riga I'll be getting the ferry across to Stockholm, then ride through Sweden, bridge to Denmark, then Ferry back to Harwich. Anyone done this route and suggestions of places to go?

Probably I wouldn't be camping, so suggestions for places to stay would be appreciated.

Thanks again.

Kalliningrad is Russia.
You need the same Visa, Insurance, Registrations etc as 'mainland' Russia. The only difference is the border personnel seem more friendly, efficient and know a little more English. Probably a result of seeing more Westerners - or the Prussian origins of the region and its people.

Update on Poland from my May post.
I crossed again last month on a similar journey. Main roads are good and some being extensivly upgraded (good old EU taxpayers, you and me). Traffic conjestion often bad, except on motoway. Tolls on the west/east motorway which avoids Poznan are avoidable by coming off at the junction before, and rejoining at the junction after, each of the 3 toll-barriers! The toll barriers are shown on Michelin maps and are only on the western section of the motorway. The cost is 11PLN, about £2.70 (same for cars and bikes) at each barrier.
Speed cameras are plentyful but only in speed limit zones, villages etc and are signed in advance.
As in Ireland, there is extensive use of the hard shoulders to allow overtakers. Even oncoming traffic does it, to help!

I traveled through Poland for the last two years ..

It was ok...never felt uneasy or insecure ... friendly people ..

but signing is poor ... you can easly get lost which was also fun. Ended up very nice places ... :)

Stayed in a very interesting/friendly/unique village in the south of Poland ,near Zakopane a few weeks ago. 'Chocholuw'. Good spot! #37 is a good place to stay.
Cheers, Boot.