I honestly do not understand why children are no longer taught cursive at school. Yes, most people prefer to type these days, but I wouldn't rush to declare handwriting entirely obsolete. After all, unless one has a disability that makes it impossible for him or her to hold a pen, one's hands are always ... well... at hand.
A journal is eminently more suitable for keeping one's travel notes than a blog. It can be any size one wants - from something that fits into a jacket pocket to a full-size leather-bound Levenger creation with pockets for mementos and room for photos and illustrations. A blog, on the other hand, requires a laptop with spare batteries, a power source and possibly a converter, if one is traveling outside of the United States and Canada. Alternatively, one must always be able to find a place equipped with computers, which severely limits the travel options.
A journal does not require an internet connection, it does not crash or run out of battery power. Yes, most major cities have internet cafes, where one could connect up, but what of other, more remote areas? Try finding an internet cafe in a coastal village in Portugal or somewhere in the Himalayas. Would it not be better to keep hand-written notes, especially if the nearest outpost of civilization with running water, electricity and internet connection is days away? No matter how vibrant one's impressions are, the memory can only hold so much, and waiting to blog them carries the risk of losing some key bits and pieces. Where was it that you saw that incredible butterfly or ate that amazing fish soup? Write it down - your account of an event might not go out as quickly, but it will be as fresh as if it only just occurred.
A journal can be taken anywhere - to a park, to a museum, to a cathedral, on a lengthy hike or a canoe trip. There are tons of inexpensive options - from a reasonably sturdy and well-sealed ziplock bag to specially designed water-proof containers - to keep the precious notes protected from the elements while adding virtually no extra weight to one's luggage. There are pens and pencils with water-resistant pigments protecting one's writing, even if the journal gets wet. Maintaining and protecting a computer in tough climatic conditions is a lot more complicated and a lot less full-proof.
A journal and a good digital camera (with a good water-proof case, a large memory stick, a small converter and a rechargeable battery) make a truly fine combination to create a thorough and detailed record of one's journey. One might find it helpful to go through the photos and record the image numbers with the appropriate journal entry to avoid confusion. Finally, let us not forget that as recently as the last century travelers' letters and drawings sometimes took months to get to the audience. Do you honestly think that the world would collapse, if you wait to send your travel entries into the world a few days or weeks later? In addition, creating a blog based on the existing journal entries allows one to edit and polish the material before it gets to the audience, thus giving the audience a higher-quality and more vibrant account of one's journey.