I've lowered the price on my barwen.ch shell accounts to 0.025 BTC per month (they used to be 0.5 BTC per month, when the rate was lower).
The accounts are small, but enough to run eggdrop, irssi, simple CGI scripts or for pinging and tracerouting places.
You need to make a first payment by verified paypal (for USD 0.50) so I can get some vague ID of who you are, and after that you can pay by BTC for subsequent months.
more specs here: http://s0.barwen.ch/~benc/drupal/specs
and the signup form: http://s0.barwen.ch/~benc/drupal/signup