Hi.
I am in Britain and would like long term exposure to USD.
Could someone advise the best way to buy dollars and then invest in dollar based assets?
Are there any forex sites where I can then invest in stocks or commodities?
Any advise would be greatly appreciated.

Talk to an investment broker - as you seem so dedicated in entering forex markets, I'm presuming you've researched enough about brokerages you could use for this.

Just a reminder, too, that advertising is not permitted on the forums, and as we've been spammed a lot by forex companies, any such promotional posts made on this thread will be deleted.