Cryptocurrencies known for their rapid transaction speeds:

 Several cryptocurrencies are known for their high transaction speeds, enabling swift and efficient transfers of value across their networks.

1. Ripple (XRP): Ripple is known for its rapid transaction speeds, with transactions settling in seconds. It's designed to facilitate fast and low-cost cross-border payments, making it attractive to financial institutions and remittance services.

2. Stellar Lumens (XLM): Stellar is a blockchain platform that focuses on facilitating cross-border transactions and remittances. It boasts fast transaction confirmation times, typically taking only a few seconds to complete.

3. Nano (NANO): Nano is a cryptocurrency known for its instant and feeless transactions. It utilizes a unique block-lattice architecture, allowing each account to have its blockchain, which contributes to its fast transaction speeds.

4. Litecoin (LTC): Litecoin is often referred to as the "silver to Bitcoin's gold" and offers faster transaction times compared to Bitcoin. It has a shorter block generation time, resulting in quicker confirmations for transactions.

5. Solana (SOL): Solana is a high-performance blockchain known for its scalability and fast transaction speeds. Its architecture can handle thousands of transactions per second, making it suitable for decentralized applications (dApps) and decentralized finance (DeFi) platforms.

6. Cardano (ADA): Cardano is a blockchain platform known for its focus on scalability, interoperability, and sustainability. While its transaction speeds are fast, Cardano's development aims to further optimize its performance as it progresses through its roadmap.

These cryptocurrencies are just a few examples of projects that prioritize fast transaction speeds. However, it's essential to consider other factors such as security, scalability, and adoption when evaluating the suitability of a cryptocurrency for your needs.