Travelling around Mongolia. Public transports?

I'm planning to visit Mongolia, possibly next summer.
My main doubt is: is it possible to visit the country with public transports (bus, shared cars, etc.)? Are they enough available for many destination, reliable, and safe?
Or is it necessary to rent a jeep with driver?
Thanks for any helpful info!

You can easily catch the public transportation from UB to any province of Mongolia. But once you get one of those provice or town by public transportation, then it will be kinda hard to find any public transportations to other towns or some attractive destinations. If you want to do it by this way, you will probably travel with 20 other people in a van which has 10 seat in it!
What I recommend is:
If you are going to stay in a guesthouse in UB. Then you can join other people to share the jeep renting expenses! They could offer you a van for 50-60USD daily.
Good luck!

Quando pensi di andare in Mongolia?
Io ci sarò dall'08/06/08 (arrivo da Mosca con il TransMongolian) fino al 16/07/08 (Volo per Mosca)
Ho già prenotato Jeep con autista per il periodo 11/06 - 07/07/08 (flessibile fino al 09/07)
Ho già trovato un compagno di viaggio (canadese/23 anni) per tutto il periodo.
Ne cerco un altro per tutto il viaggio ma anche solo per una parte.
Ho un programma di massima se le tue date corrispondo te lo manderò.
Mi puoi conttatare via email guy.lamiche@tin.it e se vuoi avere un idea di chi sono http://members.virtualtourist.com/m/5b681/
Ciao

There are international trains from Beijing & Irkutsk to Ulan Bator. Public Transport in Mongolia is poor & often involves standing room only in trucks. There is a cheap public bus to Terelj Gorkhi NP from UB that leaves around 11 am in Peace Ave & returns to UB at 8am.

Your best bet is to join a tour. OTAM Eco tours were great, & around $123 for a 6 day 5 night tour.

http://www.otamecotours.com/web/

In 4 weeks, the number of foreigners in the Russian jeeps I toured in, never exceeded 5.