Jailmate Cards sell a range of prison related cards - from birthday cards to "naughty" cards that can be sent directly to the prison.
Email a prisoner allows you to top up your account and send emails directly to the prison which are then printed out and posted under their door. Typically, these only take 1 or 2 days to get to the prisoner and have been known to even get there on the same day. This can be useful if you just want to update your other half on your day or tell them something more urgent. Each email costs 35p and some prisons offer a reply service.
Prison Voicemail offers a subscription service paid for by you on the outside for a cost of £5 or £10 per month, depending on how many minutes you want to pay for. You are then given a number you can ring and leave a message on just like any normal voicemail. The prisoner can then ring this number to listen to your message and leave one back. You will get a notification to let you know they have listened and/or left a message. You only get a few minutes however this can be a nice way of leaving a little reminder, singing happy birthday or letting your child play the latest song they've learnt on the piano down the phone.
Storybook Dads allows mums and dads to record a story whilst in prison which can then be sent to their child on the outside to listen to at bedtime.

Alternatives

Aside from sending letters and receiving phone calls there are other ways of keeping in touch which may be considered easier or quicker.

Prison Phone offer a range of price plans where the loved ones on the outside pay between £5.99 and £41.99 to allow the inmate discounted calls to mobile phones. They also offer family packages to give the inmate discounted calls to multiple phones.
Inmates Rates makes calls from inside the prison cheaper, a great service if you live abroad or are often away as international calls from a prison phone can be extremely high.

Staying in touch

It's likely that you have never been so eager to see the postman as when your other half is in prison. You've also probably never spent so much on stamps! Sending and receiving letters becomes so important and gives you something you can keep and read whenever you need a reminder or pick me up. Writing can also be a much easier way of expressing how you're feeling than face to face in the intense environment of the visit hall.
Most letters going in and out of prisons tend to be read and for this reason, they can take a while to get through. This will all depend on how busy the mail room is but you are likely to wait a week or two after sending one before you get a reply. Some letters have been known to be received the following day, others 3 weeks later and so unfortunately it really is difficult to predict.

We also have lots of ideas on our 'Things To Send' page.

SUPPORT FOR THE LOVED ONES OF THOSE IN PRISONs IN THE UK