From Iguazu to Bolivia.

Since there is not much info on the web here I throw my experience as of may 1th 2009
On the Omnibus terminal in Puerto Iguazu, Argentina there is the first morning bus departing for Paraguay at 7am. Ticket costs 3 ARS. Bus makes one quick stop on the argentinian immigration side and then just passes through brazilian city Foz de Iguacu. In less than an hour of the ride you should be in paraguayan custom. Dont forget to get your passport stamped. Its better to tell the driver to stop as you might be the only one "extranjero". The bus will probably not wait for you but it is not a biggie. There is plenty of another busses passing by and you can sneak into the one with label Asuncion. I paid to the driver 60 PYG equal to 12 USD. Money change can be done in Paraguay at the border.

Asuncion is not the tourist destination which gives it some kind of charm. It is one of the cheapest cities on the planet and the city is waiting for its big times. Unfortunately all the businesses were closed because it was the may 1th the labor day. People were relaxing, drinking their yerba mate and enjoying the day. From the front of the Omnibus terminal there are local busses No. 8, 38, 14, 15 going to "el centro" of Asuncion. The fare is 2000 PYG(0.4USD).

Asuncion to Santa Cruz(Paraguay to Bolivia): From Asuncion there is more than just one operator serving this route. The cheapest I found was 'Stel Turismo'. 230PYG (46USD) leaving Asuncion at 8 pm, the quality is far behind Argentinian busses but we are on move :) . On the Paraguayan side there is fully paved road and bolivian part is muddy and dusty bumpy road. But only few kilometers to Villamontes. Then bus runs again on solid road. Arrival to Santa Cruz was sometimes in the evening on the following day.