If you like to avoid the headache everytime you want to remember them, you could use one of many applications in the market that can keep those important informations for you in your Treo device. So you can look them up whenever you need them. One great application that's up for this job is from Spb Software House called Spb Wallets v1.50, I tried one with my Treo 750v and I must say that I'm very impressed by it.
It's a little bit tricky at first, but after getting used to it; I can't stop jamming my personal infos. The card view feature is very eye-catcher, although with long texts will look crowded in Treo 750's small screen resolution. I had to adjust it so the card looks better with my Treo. You can easily write the informations you needed because of the templates within Spb Wallets are abundant, these templates will remind you of the necessary ones and mostly forgotten to written down. Besides the freedom to edit & create your own templates, Spb Software House has made plenty additional templates for download at their website. The icon card also looks interesting, makes you want to keep making them and browse to match with the infos you're making. And this Spb Wallets v1.50 have already uses 256-bit encryption automatically every time you make a new wallet with it, which pretty much is the latest standard for security wallet.
I like Spb Wallets even more because of the desktop sync is automatically transfer every thing I wrote at my Treo into my laptop, this way I can look them up when I'm using my laptop instead of Treo. The sync uses Window's mobile sync, so all you've got to do is plug it in and wait till it's finished. Fast & handy!
If just they could squeeze in one more feature; I has difficulty to always keep going back and forth to Spb Wallets because of long username or password. I wish there’s a copy and paste feature to do this, so I can easily inserted the needed infos right away.
(blogged with my Treo 750v)