I've read several articles that pipe | symbol is an excellent substitute for commas in order to separate keywords in the title tag. Just recently I was informed that the pipe symbol tells google to stop reading at that point (only relevant in title tags).

For example keyword | keyword | companyname.com
With this example google will read the two keywords and not read the company name.

Is this correct, or is it just a good divider?

as far as my experience goes it is just another divider - it does not stop the spider as far as I can tell - look at what they put up in the SERPs if they did not see it then it would be cut out of the title they list - since the title is not pulled real time as changed pages can show you

i agree with Aussie, it does not stop the spiders from crawling the rest of the title tag.

Additionally, i personally think that it can make title tags look a lot better (visually) than using hyphens, commas, and semi-colons if used properly. I think it's best to format your title tags almost as a sentence or short statement and then use the piping at the end to separate the domain name or brand.

Example: Keyword and Keyword b made of Quality Keyword C | Domain.com
or
Article Name | Domain.com
or
Site Section name | Domain.com

Its just a divider for human eyes. Has no power to stop the robots from crawling the Title Tags. It just looks good.

Search Watch

I like the "pipe." It looks more modern. It makes the title stand out more from the pack. It is growing in use in all sorts of text/word documents etc. I use a few in my titles - currently 1 in title and 4 in description.

I have not found it as a negative for search engines. However, I do believe there is some ranking preference for natural text and putting keywords in "naturally" across webpages. So yes I am interested in this question.

GAustralia

I am using | on many pages.Work perfectly fine and pages rank well for keywords in that page title.

using the pipe take away an extra character than a comma - so if you use it you have to decrease your title words