a trip
I prefer /<em>like - prefer is for comparing two things</em>/ to take pictures and keep a journal on a trip.
The main reason is that it /<em>I - :-) or if 'it' means taking pictures and keeping a journal ok, but it sounds a little odd</em>/ can keep the memory forever. Snapping a keepsake /<em>ok, I think keepsake is usually an object rather than a photo, but it's clear what you mean, maybe souvenir fits better</em> / photograph or keeping a journal can remain /<em>remind</em>/ you of what happened on this trip, whom you went with /<em>perfectly correct, but common usage is who you went with, it's up to you</em> / and how you felt about this trip. It’s quite amazing /later/ to find this information especially when some pieces / <em>again correct, but parts or bits sounds more usual</em>/ of this trip are no longer completed /<em>I would omit completed</em>/ in your mind. / especially when you have forgotten what happened during your trip./
In addition, if I post my pictures on my personal homepage, all my fans would /or can or could/ share my trip online. Thus, they have more chances to make comments on your /my/ page and interact with you /me/. Maybe you /I/ would gain more fans if your /my/ pictures are /were - subjunctive verb/ funny enough. (you could use my or your here but you need to be consistent, not switch between them)
So I have every reason to do that.
best wishes