you should really get relevant backlinks not just high pr. I bet if you where linked to google your site wouldnt be number 1 for real estate if you own a crummy little blog with 1 post.
Most people will say that any backlinks are good backlinks but I dont waste my time with these ones. I usually try to do PR4+ if at all possible!
I agree that any one way link is worth getting. It all adds up at the end of the day but I'm always on the lookout for higher pr links.
Aren't we all? Top tip: Look for relevant sites that are link baiting i.e an article that is going to cause people to argue about and link to it (they're fairly easy to spot). Odds are the pages will have high PR at some stage so make sure you're one of the first to post there
well all sites have to start somewhere so sites with PR1 or PR2 have the potential to increase and I beleive that vollume of low level PR also helps your site, not to menion that traffic helps also, I dont even think about PR when trading links, I try to keep things related, pick a site that doesnt have to many links and ones that may bring traffic lol
If you are patient links with pr1 and pr2 sites will still help you get to a certain point pagerank wise i suppose if someone just wants to increase their pr as quickly as possible they will just go for higher sites.
Any link has value. Don't worry about getting punished by the SEs because of links pointing to your site. If that was the case, it would be an easy way to eliminate your competitor from the search engines. Get as many links as you can. That's the general rule.
You should be looking for links related to your content regardless of the PR. Related links from content rich sites will boost your search engine rankings. Which will get more people looking at your site. Which will get you more related links. Which will boost your search engine rankings...and oh yeah...boost your PR.