Hasslewise: I was traveling with my partner, she had to wear the hijab (hair covering) at all times while outdoors which was a bit of a challenge (try keeping it on with the wind blowing out of the metro in Tehran!). People are very accommodating though, a huddle of women would sometimes form around her to set things right if it was slipping off! This was exacerbated by the time of year (midsummer), you'd be better going sometime cooler. Only other thing I can think of is that the banking system is totally cut off from outside (no ATMs which accept foreign cards, very few places accept western credit cards), so you need to carry in as much cash as you need for the trip. Definitely intending to go back in the future with more time on our hands - there's just endless places to see and visit - it truly was a unique experience.
We've got some blog posts here that might help: http://www.sarahandniall.com/2011/08/iran.html http://www.sarahandniall.com/2011/09/traveling-as-woman-in-i... (I have blog posts written but not published for the rest of the trip - really must get them up!).
If you happen to come back here I'd be glad to show you around town (Santa Cruz de la Sierra) and grab a coffee or something like that.
Edit with more details:
Choosing where to go: get a big map and an imagination!
Flights: Just booked mine as I went and that seemed to work out well costwise. In any case try to overland as much as possible, it's more interesting.
Packing: Bring as little as possible, I had a 50+10L backpack and it was more than adequate. Every litre extra you pack is more and more hassle when moving.
Visas: This obv depends on where you're from and where you're headed. I sorted visas for Iran and India before leaving home (Ireland). Generally what the article says is true, it's usually possible to throw some money at the problem and get visas while on the move if necessary. Some visas run from time of entry, some from time of issuance (particularly India) - pay attention to this!