It's a pet subject of mine actually, have ranted about this
before. The Continental lounge in LGW S has free wifi, but that's about the only other lounge apart from HKG where I have found this. The cost of a bottle of Cuvee Louise a month would more than pay for the service.
ADSL WIFI Router - £50
Monthly ADSL connection - £15
Happy traveller - PRICELESS!