Some time in the distant future—say six months from now—I’ll probably look back at this post the same way we look at our dusty VHS players wasting away in a corner of the attic. In my humble opinion, these are the best free or low-cost tools available today to help companies market online. These are my opinions only. No hate mail, please.

Professional Networks: I like LinkedIn over Plaxo. Sorry Plaxo.

Social Networks: I’ve seen an explosion of Facebook activity among my professional friends in the past few months. Don’t forget to do corporate and personal accounts. The old corporate “pages” were practically worthless, but the new version is better.

Blogs: WordPress has excellent functionality and can operate from their server or yours. WordPress has some great add-ins, including Add-to-Any and several good RSS and Twitter sync options.

Microblogs: At the moment, Twitter is still on fire, especially among twentysomethings. I prefer the status update feature on Facebook, but I’m doing both.

URL Trimmer: I like bit.ly. It helps you save your precious 140 characters on your tweets, while adding some great tracking functionality

Keyword Research: I recommend starting with Google’s keyword tool. It’s easy, free and shows the relative competitiveness of various terms: https://adwords.google.com/select/KeywordToolExternal. While you’re learning about keywords to target, don’t forget that you’re looking at some rich insight about your customers and what they want. What you see might surprise you and reveal new opportunities.

SEO Analysis: The folks at HubSpot have developed website.grader.com, which can provide some insightful feedback. It’s more technical than most users will understand and it will discover areas for improvement with nearly any site, but I think it’s based on sound SEO principles. While most people are thinking about Google, don’t forget Yahoo and MSN.

Social Bookmarks: Digg, Delicious and Stumbleupon seem to be getting the most traction.

Newsletter: Constant Contact remains our email newsletter of choice. It’s affordable, works well and will help you stay on the right side of the CAN SPAM laws.

Video: Finally, YouTube may be the Google of video, but don’t forget Google Video.