This post has been updated as of February, 2020. SteemConnect is no longer supporting account creation. Below are alternative signup methods that can be used instead.
BlockTrades
BlockTrades allows you to create a new account instantly using BTC, LTC, ETH, STEEM, and other cryptocurrencies. The charge is for the blockchain account creation fee, plus a small additional fee for using their service. BlockTrades does not require you to have an existing Steem/Steemit account.
https://blocktrades.us/create-steem-account
BuildTeam
BuildTeam allows you to create a new account instantly using BTC, LTC, Dash, BTS, STEEM, and other cryptocurrencies. The charge is for the blockchain account creation fee, plus a small additional fee for using their service. BuildTeam does not require you to have an existing Steem/Steemit account.
https://account.buildteam.io/apps/steem-account
AnonSteem
AnonSteem will allow you to create an account by paying the account creation fee, plus an additional fee for using their service. They accept STEEM, bitcoin (BTC), and Litecoin (LTC). AnonSteem does not require you to have an existing Steem/Steemit account.
https://anon.steem.network/
Actifit
Actifit will allow you to create an account by paying the account creation fee, plus an additional fee for using their service. They currently only accept STEEM. Actifit does not require you to have an existing Steem/Steemit account.
https://actifit.io/signup