Forum Moderators: open
Welcome to Webmaster World.
Yep, Google usually ignores punctuation, and in this case, even if you use a quoted search (":") it's going to refuse because you're basically asking it to return every page in it's index.
You'll have more luck if you can narrow down the search somewhat...
a +: (all pages with the letter a plus colon)
":" site:.com (all .com tld pages with a colon)
And, if you can excuse my denseness, why in the world do you have to find pages that contain a colon? The must be billions of them.
The 2 suggestions above are just searching for the valid terms and are ignoring the +: part (i.e. all pages with the letter a and all .com sites respectively).
[webmasterworld.com...]
And I'd also recommend checking out some of the other DMOZ search categories:
[dmoz.org...]
And, if it's submitting your site for link exchanges, you might want to do some reading at WW's Link Development forum...
[webmasterworld.com...]
...and some of the articles in its library:
[webmasterworld.com...]
Some quick tips to search for what you need might be phrases like:
YourIndustry directory
YourIndustry link exchange
YourIndustry web resources
Internet YourIndustry directory
Internet YourIndustry resources
Submit YourIndustry site
Submit YourIndustry link
And other phrases along those lines, substituting your site's business for YourIndustry.