I am loving this cool service Dial2Do. It uses voice command to do all types of different functions such as send a text or email, update your twitter status, leave yourself reminders, and add notes to Evernote. The service is free but you'll need to set up an account and Dial 2 Do will provide you with a phone number to add to your mobile phone. Then, you just dial the number and you'll be asked what you'd like to do.
I use this service frequently to send a text message to family as I'm walking through the parking lot after work to let them know if I'm running late or need to make a stop on my way home. I use the reminder feature quite a bit too. I have been known to be sitting at a stoplight and suddenly remember that we are running low on dishwasher detergent, so I'll hit Dial2Do on speed dial, say 'reminder: buy dishwasher detergent' and when I get home there is an email reminder in my inbox and I can then add detergent to my shopping list! If you are an Evernote user you can also send notes directly to your notebooks. If you aren't an Evernote user, hang tight, I'll be writing up a review on that soon.