An occurring trend I've noticed around Forrst (as well as other websites) is a serious lack of communicative skill. It's deeper than avoiding words like 'lol' - people seem to have little understanding of structured sentences and appropriate punctuation. I'm far from being an English teacher, but I'd say that your communicative skill is one of your most valuable portfolio items.
When it comes to communication in the real world, it's a big deal for clients. Many of my clients have needed help with their website after it's launch - whether this be a video, a one-to-one teaching session, or most favorable, a document outlining the basics of the site. If you lack the proper communication skills or understanding of the words you're writing, then this document will serve no purpose and could confuse the reader even more. Little things - like the misplacement of apostrophes - will put off users, particularly potential employers.
Take the time to learn about the different uses for punctuation - correct placement of apostrophes, commas, semicolons, and dashes. If you're using WordPress, you can install the WP-Typography plugin. It automatically replaces straight quotes etc with smart quotes and other fancy typographic things. Keeping up a blog has been a tremendous help toward the development of my communication skills - you find yourself reading over the things you had written and thinking "That doesn't make any sense".
Your clients and employers will be impressed if you have good communicative skills - some of my clients have been surprised by my ability to write and communicate. It helps especially for those clients that regard content as a part of the package (which happens more often than not, I can tell you). There is a lot of information on this topic available at A List Apart, and it goes hand in hand with Content Strategy. I would recommend getting a copy of Erin Kissane's book "The Elements of Content Strategy". While it has little to say in regard to actual language, it gives a myriad of tips on internal and external communication and content delivery.