I've kept travel journals for many years. They now take up half a shelf in one of our bookcases.
I find them a great accompaniement to the massive number of travel photo folders in my computer.
They are all bound blank books that I've gotten at bookstores or stationary stores. I almost always buy one when I'm in Venice- gorgeously bound and covered, and of good quality paper. There's something very relaxing about sitting down in the evening with a glass of wine and recording my thoughts on what we've seen that day. Or catching up while sitting on a train.
Since the books are big enough to record multiple trips, I always put a note on the front page with the dates and locations inside the journal. That makes it much easier when I want to look back at a particular place. It's surprising how often I do that, especially when planning a trip to a place we've been before. Or someone will ask for recommendations about hotels or restaurants, etc.
Electronic records are fine for some. But give me a real paper journal and a pen any day.