Following our report on Wednesday that Twitter will stop sending mobile SMS updates to users in countries other than the United States, Canada and India, several startups have stepped forward to say they’ll help out (for a reasonable fee).

To recap, Twitter found that it was being charged unreasonable amounts — up to $1,000 per user — in areas like Europe to send SMS messages to users, because of different billing standards. In the US, Twitter makes some money from SMS, because carriers will cut them a portion of the fee they charge their users for both incoming and outgoing messages.

Zygotweet is an effort thrown together by the United Kingdom company Zygohubs, a sort of centralized messaging service that already ties into mobile. They’ve put together a form for Twitter users to request a service that would charge about 5 pence per incoming message from Twitter (the service wouldn’t try to send all messages, just those directed to you). A nearly identical idea, tweetSMS, is already online, and got covered on Mashable.

Whether Twitter’s user base is large enough to provide meaningful revenue to startups in other countries is unknown. Chances are good that Twitter has well over a quarter million users in the United Kingdom — its US traffic numbers have grown rapidly, and it took off early this year in the UK — so if just a portion of those care enough to get SMS service, there’s some revenue to be had.

It seems odd that the company would sacrifice the money when it has already said it’s interested in mobile and SMS, but Twitter does have a history of letting other companies step in and create features it should have made itself.